• 


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The    University    of  /Washington 
Department  of  Chemistry 


of  A 


PRESERVATION  OF  IRON  AND  STEEL 

BY  MEANS  OF  PASSIVIFYING 

FACTORS 


BY 


THOMAS  GORDON  THOMPSON 


A  Thesis  Submitted  in  Partial  Fulfilment  of  the  Requirement 
for  the  Degree  of  Doctor  of  Philosophy 


SEATTLE,  WASHINGTON 
1920 


The    University    of    Washington 
Department  of  Chemistry 


BY 

THOMAS  GORDON  THOMPSON 


A  Thesis  Submitted  in  Partial  Fulfilment  of  the  Requirement 
for  the  Degree  of  Doctor  of  Philosophy 


SEATTLE,  WASHINGTON 
H.    C.    PIGOTT    PRINTING    CONCERN 

1920 


PRESERVATION    OF    IRON    AND    STEEL    BY    MEANS    OF 
PASSIVIFYING   FACTORS. 

PASSIVITY. 

When  iron  is  immersed  in  solutions  of  chromic  acid  or  potassium  dichro- 
mate 1  for  a  few  hours,  treated  with  concentrated  nitric  acid  or  made 
the  anode  of  an  electric  circuit  in  certain  electrolytes,  it  becomes  very  inert. 
This  phenomenon  is  known  as  passivity.  Thus,  for  example,  if  a  piece  of 
iron  or  steel  be  placed  in  a  solution  of  copper  sulphate  for  a  brief  period, 
metallic  copper  will  deposit  upon  the  surface.  If,  however,  the  iron  has 
been  "passivified"  by  immersion  in  potassium  dichromate  or  concentrated 
nitric  acid,  this  reaction  will  not  take  place  until  the  passivity  has  been 
destroyed.  A  further  test  for  passivity  is  found  in  the  fact 2  that  the  iron 
will  not  dissolve  in  nitric  acid  having  a  specific  gravity  of  1.20.  Should  iron 
be  placed  in  concentrated  nitric  acid,  the  metal  will  begin  t'o  go  into  solu- 
tion rapidly  and  then  suddenly  all  chemical  action  will  cease.  Upon  applying 
the  above  tests  it  will  be  found  that  the  iron  is  in  the  passive  state.  If 
iron  be  made  the  positive  electrode  and  placed  in  certain  electrolytes  and 
the  amount  of  current  flowing  is  sufficient,  it  will  be  noted  that'  the  iron 
will  not  go  into  solution  according  to  Faraday's  law.  The  iron  will  be 
pbssivified,  the  rate  of  solution  reduced  to  a  minimum,  and  bubbles  of 
oxygen  will  arise  from  the  anode. 

Many  explanations  of  this  peculiar  phenomenon  have  been  offered,  and 
the  subject'  has  claimed  the  attention  of  a  vast  number  of  investigators. 
No  really  satisfactory  explanation,  generally  acceptable  and  capable  of 
explaining  the  passive  condition  of  metals  under  all  circumstances,  has, 
however,  ever  been  advanced.  Many  investigators  are  supporters  of  the 
so-called  oxide  and  gaseous  film  theories.  A  complete  bibliography  of  the 
literature  relating  to  passivity  up  to  1907  is  given  by  Heathcote 3  and  by 
Byers.4  A  symposium,  "The  Passivity  of  Metals,"  published  by  the  Faraday 
Society  in  1913,  gives  outlines  of  the  more  recent  work  upon  this  subject. 
A  very  clear  and  comprehensive  chapter,  ''The  Passive  State  of  Iron,"  is 
given  by  J.  Newton  Friend  in  his  interesting  book,  "The  Corrosion  of  Iron 
and  Steel." 

That'  other  metals  besides  iron  may  be  rendered  passive  has  been  pointed 
out  from  time  to  time  by  various  investigators.  Thus  Dustan  and  Hill 5 
describe  means  for  producing  the  passive  state  of  zinc,  together  with  a 
number  of  other  metals.  The  effect  of  potassium  dichromate  upon  zinc, 
when  used  as  a  galvanising  agent,  will  be  discussed  in  the  experimental 
portion  of  this  Report. 


1  Dunstan    and    Hill    (Jour.    Chem.    Soc.,    vol.    99,    pp.    1833-53)    have    demonstrated    that 
many  other  salts  besides  the  dichromates  may  be  utilised  as  passivifying  agents. 

2  Heathcote,   Jour.   Soc.    Chem.    Ind.,    1907,   vol.    26,    p.    899. 

3  Heathcote,  Jour.  Soc.  Chem.  Ind.,  1907,  vol.   26,  p.  899. 

4  Jour.  Am.  Chem.  Soc.,  1908,  vol.  30,  p.   1718. 
3  Jour.  Chem.  Soc.,  vol.   99,  pp.   1853-67. 


425704 


6 

PASSIVITY    AND    ITS    RELATION    TO    THE    CORROSION    OF 

IRON  AND   STEEL. 

Passivifying  Agents   as   Pigments. 

Although  the  phenomenon  of  passivity  has  been  known  since  1794,  no 
attempt  was  made  until  quite  recently  to  make  use  of  this  peculiar  fact  as 
a  means  for  preventing  or  inhibiting  the  corrosion  of  iron  and  steel.  In 
1895  M.  P.  Wood '  called  attention  to  the  valuable  properties  possessed  by 
insoluble  and  basic  chromates  when  used  as  protective  coatings  for  iron 
and  steel.  The  use  of  such  materials,  when  properly  applied,  has  been 
confirmed  by  all  investigators  in  this  particular  field.  The  work  of  Gush- 
man  has  done  much  to  demonstrate  the  value  of  chrome  pigments. 

Soluble  Passivifying  Agents  in   Steam  Boilers. 

The  corrosion  of  steam  boilers  takes  place  under  conditions  very  dif- 
ferent from  those  encountered  in  the  ordinary  corrosion  of  iron  and  steel. 
The  gases  dissolved  in  the  boiler  water  at  atmospheric  temperatures  are 
rapidly  removed,  to  a  very  large  extent,  upon  heating,  thereby  decreasing 
the  relative  corrosivity  of  the  water.  However,  other  factors  are  present 
that  will  stimulate  corrosion  within  the  boiler.  Briefly,  these  are  the  lack 
of  homogeneity  of  the  boiler  plates,  contact  of  the  plates  with  dissimilar 
metals,  the  effect  of  strains,  and  the  influence  of  dissolved  salts.  The  nature 
of  these  dissolved  salts  determine  to  a  great  extent  the  corrosive  action  that 
goes  on  within  the  boiler. 

From  the  work  of  Grave '  and  Moseley  3  it  might  be  concluded  that  the 
chemical  composition  of  the  boiler  plates,  their  lack  of  homogeneity,  and 
the  effect  of  strains  would  have  very  little  to  do  with  the  ease  with  which 
the  plates  could  be  passivified. 

The  use  of  soluble  chromates,  such  as  potassium  dichromate,  as  a  means 
for  preventing  corrosion  in  boilers,  was  first  recommended  by  Cushman.4 
He  suggested  the  use  of  5  Ibs.  of  potassium  dichromate  to  1500  gallons  of 
water.  When  this  was  tried  on  a  commercial  basis,  it  was  found  that  the 
potassium  dichromate  had  practically  no  influence  in  limiting  corrosion. 
Archbutt5  found  that  when  potassium  dichromate  was  added  to  the  con- 
centrated boiler  water,  corrosion  was  not  prevented,  "especially  in 
locomotive  boilers  where  metallic  copper  is  in  contact  with  the  boiler." 
Under  such  conditions  it  would  be  impossible  to  maintain  the  passive  state. 
The  exact  nature  of  the  dissolved  salts  was  not  stated.  Friend  and  Brown  6 
have  studied  the  effect'  of  potassium  dichromate  and  potassium  chromate 
in  varying  concentrations  in  a  number  of  solutions  of  sodium  chloride 
ranging  from  fairly  dilute  to  saturated.  Tests  were  run  for  a  few  days 


1  Trans.  Am.  Soc.  Mech.  Eng-.,  vol.  16,  p.  671. 
2Z.  physik  Chem.,  vol.  77,  pp.  513-76. 

3  Jour.  Am.  Chem.  Soc.,  1915,  vol.  37,  pp.  2326-34. 

4  United  States  Department  of  Agriculture,  Office  of   Public  Roads,   Bulletin  No.   30. 

5  Engineering,  vol.  93,  p.   824. 

6  Journal  of  the  Iron  and  Steel  Institute,  1911,  No.  I,  p.  125. 


at  room  temperature  and  at  95°  C.  With  the  potassium  dichromate  in 
sodium  chloride  corrosion  took  place  readily  both  in  the  cool  and  hot  solu- 
tions; and  it  was  found  that  corrosion  increased  with  the  increase  in 
concentration  of  the  dichromate.  However,  with  potassium  chromate,  increase 
in  concentration  of  this  salt  in  the  presence  of  the  sodium  chloride  caused 
decrease  in  the  rate  of  corrosion.  The  point  at  which  corrosion  was  prac- 
tically eliminated  corresponded  with  the  presence  of  an  amount  of  dichromate 
which  would  have  cost  so  much  on  a  commercial  basis  as  to  make  its 
application  prohibitive.  The  tests  of  Friend  and  Brown  at  95°  were  con- 
ducted for  just  three  days,  and  during  that  time  the  solutions  were  heated 
only  twelve  hours  a  day,  the  solutions  being  allowed  to  cool  to  room 
temperature  over  night.  While  this  treatment  stimulated  corrosive  action, 
the  results  do  not  represent  the  true  action  of  sodium  chloride  and  potassium 
dichromate  at  95°  C. 

As  the  great  majority  of  boiler  waters  are  practically  free  from 
chlorides,  it  seems  probable  that  corrosion  would  be  inhibited  in  waters 
containing  sulphates  alone  if  the  water  were  treated  with  proper  amounts 
of  potassium  dichromate.  No  quantitative  data  has  yet  been  secured  with 
mixed  sol  itions  of  varying  strengths  of  sulphates  and  potassium  dichromate. 
Cushman  1  has  shown  qualitatively  that  with  the  increase  of  copper  sulphate 
in  solutions  containing  uniformly  small  amounts  of  potassium  dichromate, 
the  rate  at  which  the  copper  was  deposited  was  increased. 

t 

Anodic  Passivity. 

The  possibility  of  making  a  boiler  the  anode  in  an  electric  circuit  was 
suggested  by  Byers  and  Voris.2  They  were  able  to  keep  iron  passive  when 
it  was  used  as  an  anode  and  placed  in  an  electrolyte  consisting  of  sodium 
chloride  and  potassium  dichromate,  there  being  forty  times  as  much  potas- 
sium dichromate  as  sodium  chloride.  The  electrolyte  was  heated  so  that 
a  pressure  of  from  20  to  50  Ibs.  per  square  inch  was  obtained.  As  there  are 
so  many  factors  that  would  tend  to  destroy  this  passivity  in  an  ordinary 
steam  boiler,  it  therefore  seems  very  doubtful  whether  this  form  of  passivity 
would  be  of  any  real  practical  value.  With  the  increase  in  concentration  of 
the  boiler  water,  the  increase  in  the  amount  of  the  potassium  dichromate 
would  have  to  be  forty  times  that  of  the  sodium  chloride,  and  this  very  fact 
would  render  the  cost  of  operation  impossible.  No  work  has  yet  been  done 
showing  the  effect  of  the  dichromate  with  the  various  sulphates  commonly 
found  in  boiler  waters,  when  the  iron  or  boiler  is  made  the  anode  in  an 
electric  circuit. 


PURPOSES  OF  THIS  RESEARCH. 

Sjnce  the  corrosion  problem  is  so  vast  in  extent,  the  author  has  limited 
himself  to  studying  the  means  for  preventing  corrosion  in  steam  boilers  and 
receptacles  for  containing  water  for  purely  industrial  purposes.  The  object 


1  Cushman  and  Gardner,   "Corrosion  and   Preservation   of  Iron  and   Steel,"   p.   113. 

2  Jour.  Am.  Chem.  Soc.,  1912,  vol.  34,  pp.   1368-79. 


of  this  research  is  to  study  the  effect  of  various  passivifying  agents  upon 
the  rate  of  corrosion  of  different  grades  of  iron  in  solutions  of  salts  com- 
monly occurring  in  boiler  waters.  The  experimental  work  may  be  divided 
into  four  parts : 

First :  To  ascertain  the  effect  of  varying  amounts  of  potassium  di- 
chromate  in  solutions  of  different  concentrations  of  sodium  chloride,  sodium 
sulphate,  calcium  sulphate,  magnesium  chloride,  and  magnesium  sulphate 
at  room  temperature  and  at  the  temperature  of  boiling  water. 

Since  the  publication  of  the  suggestion  of  the  use  of  potassium  di- 
chromate  as  a  means  for  preventing  boiler  corrosion,  many  text-books  have 
been  published  which  mention  the  use  of  potassium  dichromate  as  a 
preventive  for  corrosion.  It  is  the  aim  of  the  author  to  present  sufficient 
data  to  establish  definitely  the  truth  or  fallacy  of  this  statement. 

Second :  To  determine  the  efficiency  of  di-sodium  phosphate  as  an 
inhibitive  agent,  the  samples  of  iron  and  steel  being  placed  in  the  above- 
mentioned  solutions. 

Third :  To  secure  data  regarding  the  action  of  zinc  or  galvanised  iron 
in  various  solutions  of  sodium  chloride  and  sodium  sulphate  containing 
varying  amounts  of  potassium  dichromate. 

Fourth :  To  determine  the  practicability  of  keeping  iron  passive  with 
potassium  dichromate  in  the  presence  of  the  salts  characteristic  of  boiler 
waters,  when  the  iron  is  made  the  anode  in  an  electric  circuit  and  heated  to 
a  pressure  varying  from  120  Ibs.  to  150  Ibs.  per  square  inch. 

EXPERIMENTAL. 

The  Nature  and  Preparation  of  the  Samples  of  Iron  and  Steel. 

The  test-pieces  used  in  all  the  following  experiments  consisted  of  a 
commercially  pure  iron  and  a  low  carbon  steel,  both  of  which  had  been 
rolled  into  sheets.  The  author  is  indebted  to  the  American  Rolling-Mill 
Company  of  Middletown,  Ohio,  who  kindly  supplied  him  with  samples  of 
their  manufacture.  The  following  shows  the  composition  of  the  test-pieces: 


Carbon 

Commercially 
Pure  Iron. 
Per  Cent. 
0.012 

Low  Carbon 
Steel. 
Per  Cent. 
0.112 

Phosphorus 

0.004 

0.045 

Silicon 

0.001 

0.003 

Sulphur 

0.017 

0.052 

Maneanese 

0.015 

0.388 

For  the  corrosion  tests,  plates  having  a  surface  of  42  square  centimetres 
were  cut -from  the  sheets,  the  plates  being  8  cm.  X  2l/2  cm.  After  cutting, 
a  small  hole  was  punched  at  the  top  of  each  plate  so  that  it  could  be 
attached  to  a  thread  and  suspended  in  solution.  The  plates  were  then 
numbered  and  pickled  in  a  solution  of  dilute  sulphuric  acid  until  all  foreign 
matter  was  removed  by  washing  rapidly  and  thoroughly  in  water  and  then 


treating  with  alcohol,  ether,  and  finally  with  gasoline.  After  the  latter 
had  evaporated  from  the  surfaces  of  the  plates  by  holding  them  over  a 
source  of  indirect  heat,  they  were  placed  in  desiccators  containing  calcium 
chloride  and  eventually  weighed. 

Preparation   of   Solutions. 

Normal  solutions  of  sodium  chloride,  sodium  sulphate,  magnesium 
chloride,  and  magnesium  sulphate,  and  a  saturated  solution  of  calcium 
sulphate  at  20°  C.  were  made.  From  the  first'  four  solutions,  N/10,  X/100, 
and  X/1000  solutions  were  prepared.  A  solution  of  potassium  dichromate 
containing  100  grammes  of  the  salt  per  litre  and  a  normal  solution  of 
di-sodium  phosphate  were  also  made.  Small  amounts  of  these  solutions 
were  measured  into  the  bottles  in  which  the  individual  corrosion  tests  were 
to  be  run,  so  that  when  the  other  solutions  were  introduced  they  would  also 
contain  either  a  thousandth  or  a  hundredth  part  of  an  equivalent  weight  of 
potassium  dichromate  or  sodium  phosphate.  Amounts  of  these  two  latter 
substances  were  weighed  out  and  placed  in  the  various  solutions  so  that 
they  gave  strengths  of  either  N/10  or  N/5. 

In  mentioning  the  normality  of  a  potassium  dichromate  solution  no 
reference  is  meant  to  its  oxidizing  power.  A  normal  solution  of  the 
dichromate  is  considered  here  as  containing  half  the  gramme  molecular 
weight. 


Apparatus. 

In  running  the  corrosion  tests  at  room  temperature,  one  plate  was 
placed  in  each  bottle.  The  bottles  were  of  300  cubic  centimetres  capacity, 
and  were  arranged  in  such  a  manner  as  to  permit'  the  passage  of  a  slow 
stream  of  air  through  the  solution.  Five  of  these  bottles  were  placed  in 
series  without  the  slight  increase  in  pressure  in  the  first  few  bottles  having 
any  effect  upon  the  rate  of  corrosion.  The  outlet'  tube  was  so  far  above  the 
surface  of  the  solution  that  any  danger  of  particles  of  the  liquid  being 
carried  over  into  the  next  bottle  was  practically  eliminated. 

The  apparatus  used  for  determining  the  rate  of  corrosion  at  the  tem- 
perature of  boiling  water  consisted  of  three  large  tin-plated  tubs,  in  which 
the  bottles  containing  the  individual  test-plates  were  placed.  These  tubs 
were  heated  by  means  of  gas-burners,  the  water  being  supplied  by  means 
of  a  constant  leveling  device  shown.  Two  of  these  devices  were  utilized 
for  each  tub,  so  that  an  accident  to  one  would  prevent  the  water  from  boiling 
away  during  the  night.  The  bottles  containing  the  plates  were  stoppered 
with  wooden  plugs,  which  had  previously  been  steamed  and  then  wrapped 
with  tinfoil.  These  plugs  were  loosely  fitted  in  order  that  the  volume  of 
gases  could  regulate  itself  without  difficulty  upon  heating.  A  wooden  rack 
supported  the  bottles  within  the  tub.  A  cover,  with  a  few  small  holes  for 
the  escape  of  steam,  fitted  securely  over  the  top  of  the  apparatus. 


10 
Conditions  Under  Which  the  Tests  were  Run. 

In  order  to  promote  corrosion,  should  it  occur,  as  rapidly  as  possible 
at  room  temperature,  air  was  slowly  bubbled  through  the  solutions.  The 
air  was  thoroughly  washed  in  a  series  of  wash  bottles  and  permitted  to  pass 
through  the  solutions  ten  hours  every  day.  This  produced  two  important 
factors,  namely,  keeping  the  solutions  saturated  with  oxygen  and  insuring 
the  homogeneity  of  the  liquids  by  constant  stirring.  All  the  tests  were 
performed  in  a  laboratory  free  from  direct'  sunlight. 

The  bottles  used  to  contain  the  solutions  and  test-plates  for  treatment 
at  100°  C.  were  subjected  to  the  action  of  boiling  water  for  twenty  hours 
a  day  for  two  weeks,  before  they  were  utilised  for  running  the  corrosion 
tests.  During  this  time  they  were  removed  each  day  from  the  tub,  emptied, 
cooled,  and  washed,  then  refilled  and  returned  to  the  tub.  The  test-plates 
were  not  suspended  in  the  solutions  but  were  laid  diagonally  across  the 
lower  end  of  the  bottle,  with  just  tire  four  corners  touching  the  sides. 

Cleaning   the   Test-Plates. 

The  rust  which  had  collected  on  the  test-plates  run  at  room  temperature 
was  removed  by  treatment  with  either  ammonium  citrate  or  dilute  sulphuric 
acid.  Ammonium  citrate,  after  treatment  for  a  little  time,  removed  the 
rust  from  the  plates  immersed  in  solutions  containing  no  potassium  di- 
chromate  or  sodium  phosphate,  or  very  small  amounts  of  these  substances. 
Sulphuric  acid  had  to  be  resorted  to  in  order  to  remove  the  rust  formed  on 
some  of  the  plates  which  had  been  in  solutions  containing  N/10  and  N/5 
dichromate.  In  cases  of  this  nature  the  rust  was  always  in  the  form  of 
hard  minute  spots.  With  the  solutions  containing  the  larger  amounts  of 
sodium  phosphate,  the  corrosive  material  was  of  a  peculiar  nature,  it  being 
a  dull  green  colour  which  always  occurred  in  the  form  of  streaks  or  large 
spots  on  the  metal.  These  streaks  and  spots  could  be  easily  removed  by 
gently  rubbing  with  the  fingers.  After  cleaning  and  washing  the  plates 
were  dried  in  the  manner  previously  described. 

With  the  tests  run  at  the  temperature  of  boiling  water  it  was  impossible 
to  clean  the  plates.  Long  immersions  in  ammonium  citrate  for  two  and 
three  days  had  no  desirable  effect.  On  the  other  hand,  if  the  plates  were 
treated  with  sulphuric  acid,  part  of  the  very  thin  scaly  material  covering 
the  plate  would  be  removed  while  the  remainder  would  still  be  intact,  and 
before  this  could  be  removed  portions  of  the  exposed  metal  would  begin  to 
dissolve.  After  a  number  of  various  attempts  to  clean  these  plates,  it  was 
finally  decided,  after  washing  with  water  and  alcohol  and  drying,  to  weigh 
them  directly.  In  the  great  majority  of  cases,  no  test  for  iron  was  obtained 
in  the  solutions,  and  thus  weighing,  without  cleaning,  probably  gave  fairly 
accurate  results. 

The  spots  occurring  on  the  plates  after  immersion  in  the  hot  solutions 
containing  potassium  dichromate  were  invariably  of  black  or  brownish-black 
colour.  Those  in  solutions  containing  larger  amounts  of  sodium  phosphate 
were  of  the  characteristic  dull  green  colour. 


11 


ACTION  OP  SOLUTIONS  OF  CHLORIDES  AND  SULPHATES  UPON 
IRON  AND  STEEL  AT  ROOM  TEMPERATURE  IN  THE  PRESENCE 
OF  POTASSIUM  DICHROMATE. 

The  following  results  show  the  effect  of  various  amounts  of  potassium 
dichromate  upon  the  rate  of  corrosion  of  iron  and  steel  when  introduced 
into  solutions  of  different  concentrations  of  chlorides  and  sulphates.  In 
some  cases  the  addition  of  dichromate  prevented  corrosion  completely, 
especially  with  the  more  concentrated  solutions  of  this  substance,  while  in 
others  its  inhibiting  character  was  very  striking. 

When  placed  in  solutions  free  from  dichromate,  the  low  carbon  steel 
showed  a  slightly  greater  tendency  toward  corrosion  than  did  the  commer- 
cially pure  iron. 

Test-plates  of  the  low  carbon  steel  and  the  commercially  pure  iron  were 
placed  in  distilled  water  and  subjected  to  the  same  treatment  as  accorded 
to  the  samples  in  the  various  solutions.  The  results  thus  obtained  were 
utilized  as  a  standard  in  computing  the  relative  corrosion.  This  was  deter- 
mined by  taking  the  loss  in  weight  of  the  samples  in  the  distilled  water  and 
dividing  into  the  loss  in  weight  by  the  test-plates  in  the  solutions*. 

Loss  in  weight  in  X  solution. 


Relative  corrosion  = 


Loss  in  weight  in  distilled  water. 


COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 
Table  I. — Action  of  Water. 


No. 

A 

B 

C 

D 


Original 

Weight. 

18.4197 

19.6435 

16.6748 

19.2308 


Loss  in 

Weight. 

0.1995 

0.2021 

0.1969 

0.1956 


Remarks. 
Badly  corroded. 


Table   II. — Potassium   Dichromate. 


Original 

Loss  in 

No. 

Normality. 

Weight. 

Weight. 

81 

1/1000 

19.8732 

0.0010 

82 

1/100 

18.8425 

0.0004* 

83 

1/10 

18.9613 

0.0000 

84 

1/5 

18.0086 

0.0001 

Relative 

Cor'sion.  Remarks. 

0          Slight  corrosion  on  edges. 

0          No   corrosion. 

0          Metal  bright. 

0 


No. 
A 
B 

C 
D 


LOW   CARBON   STEEL.     ROOM   TEMPERATURE. 
Table  III.— Action  of  Water. 


Original 

Weight. 

7.3013 

7.8240 
8.0327 
7.9241 


Loss  in 

Weight. 

0.2232 

0.2113 

0.2135 

0.2203 


Remarks. 
Badly  corroded. 


*  Gain    in    weight. 


12 


Table  IV. — Potassium  Bichromate. 


No. 

Normality. 

Original         Loss  in     Relative 
Weight         Weight.    Cor'sion.               Remarks. 

329 
330 
331 
332 

1/1000 
1/100 
1/10 
1/5 

8.4997           0.0005           0          Slight    corrosion. 
8.1320           0.0001           0          No   corrosion. 
8.1652           0.0003           0          Metal    bright. 
8.0663           0.0004           0 

COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE 

Table   V.—  Sodium   Phosphate. 

No. 

Normality. 

Original         Loss  in     Relative 
Weight.         Weight.     Cor'sion.               Remarks. 

1 

2 
3 
4 

1/1000 
1/100 
1/10 

N 

18.2439           0.2298        115           Covered    with    rust. 
19.8746           0.2203         110 
20.1324           0.1897           93 
20.4938           0.1204           59 

t  *-':•. 

Table  VI.—  Sodium   Chloride. 

No. 

Normality. 

Original         Loss  in     Relative 
Weight.         Weight.    Cor'sion.               Remarks. 

5 
6 
8 
8 

1/1000 
1/100 
1/10 

N 

20.4132           0.2133        105          Covered  with  rust. 
19.5453           0.2175         107 
19.7463           0.2556         128 
19.7077           0.1561           78 

Table  VII.  —  Magnesium  Sulphate. 

No. 

Normality. 

Original         Loss  in     Relative 
Weight.         Weight.    Cor'sion.               Remarks. 

9 
10 
11 
12 

1/1000 
1/100 
1/10 

N 

19.0452           0.2028        103           Covered   with   rust. 
18.7993           0.2468         122 
20.4995           0.1686           83 
19.5231           0.1214           55 

Table    VIII.  —  Magnesium    Chloride. 

No. 

Normality. 

Original         Loss  in     Relative 
Weight.         Weight.    Cor'sion.               Remarks. 

13 
14 
15 
16 

1/1000 
1/100 
1/10 

N 

19.8018           0.2283           113           Covered   with   rust. 
20.3402           0.1828              90 
20.2853           0.1258              62 
19.2753           0.1176              58 

LOW  CARBON  STEEL.     ROOM  TEMPERATURE. 

Table   IX.—  Sodium   Sulphate. 

No. 

Normality. 

Original         Loss  in     Relative 
Weight.         Weight.     Cor'sion.               Remarks. 

249 
250 
251 
252 

1/1000 
1/100 
1/10 

N 

8.0917           0.2597           118           Covered   with   rust. 
7.8634           0.2267           104 
7.4396           0.1648              75 
7.5003           0.1124              52 

13 


Table  X.— Sodium  Chloride. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion.              Remarks, 

253 

1/1000 

7.9239 

0.2285 

105          Covered  with 

rust. 

254 

1/100 

7.9880 

0.2332 

108 

** 

255 

1/10 

7.7302 

0.2505 

115 

" 

256 

N 

7.4951 

0.1786 

82 

Table  XI.  —  Magnesium   Sulphate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion.              Remarks. 

257 

1/1000 

7.0276 

0.2640 

122          Covered  with 

rust. 

258 

1/100 

7.8348 

0.2832 

130 

" 

259 

1/10 

8.0051 

0.1562 

72 

" 

260 

N 

8.1704 

0.1137 

52 

Table    XII.  —  Magnesium    Chloride. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion.              Remarks. 

261 

1/1000 

8.1027 

0.2529 

116          Covered  with 

rust. 

262 

1/100 

7.6020 

0.2670 

122 

" 

263 

1/10 

7.9926 

0.2218 

102 

" 

264 

N 

7.4304 

0.1893 

87 

COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 
Table  XIII.— Sodium  Sulphate  with  N/1000  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

17 

1/1000 

17.7931 

0.0190 

10 

Corrosion  around  edges. 

18 

1/100 

17.4386 

0.0165 

8 

"               "            " 

19 

1/10 

18.8439 

0.0077 

4 

Few  small  rust  spots. 

20 

N 

17.5677 

0.0132 

7 

"     large     " 

Table 

XIV.—  Sodium   Sulphate  with   N/100 

Potassium   Dichromat't. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

21 

1/1000 

18.8235 

0.0000 

0 

No  rust. 

22 

1/100 

17.9828 

0.0005 

0 

"       " 

23 

1/10 

17.8812 

0.0021 

1 

Few  minute  rust  spots. 

24 

N 

18.5079 

0.0046 

2 

Rust    around    edges. 

Table 

XV.—  Sodium    Sulphate    with    N/10 

Potassium    Bichromate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

25 

1/1000 

17.7866 

0.0001  * 

0 

Metal   bright.      No    rust. 

26 

1/100 

18.6974 

0.0005  ' 

0 

"             "             "        " 

27 

1/10 

18.5133 

0.0006  1 

0 

Several  black  spots. 

28 

N 

18.1652 

0.0043 

2 

"              "          " 

Gain    in   weight. 


14 


Table   XVI. — Sodium   Sulphate   with   N/5   Potassium   Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

29 

1/1000 

18.6887 

0.0001  1 

0 

Metal   bright. 

30 

1/100 

18.9888 

0.0002  1 

0 

"            " 

31 

1/10 

18.4944 

0.0003 

0 

Several   minuti 

32 

N 

18.5613 

0.0045 

2 

Many  minute  r 

No   rust. 


LOW    CARBON    STEEL.     ROOM    TEMPERATURE.    . 

Table  XVII.— Sodium  Sulphate  with  N/1000  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

265 

1/1000 

8.0241 

0.0112 

5 

Few 

rust  spots. 

266 

1/100 

7.0198 

0.0225 

10 

" 

"          " 

267 

1/10 

8.4727 

0.0090 

4 

" 

«          « 

268 

N 

7.9607 

0.0092 

4 

" 

"          " 

Table  XVIII. — Sodium  Sulphate  with  N/100  Potassium  Bichromate. 


Original 


Loss  in     Relative 


No. 

Normality. 

Weight 

Weight. 

Cor'sion. 

Remarks. 

269 

1/1000 

6.7617 

0.0001 

0 

No  corrosion. 

270 

1/100 

6.7436 

0.0033 

2 

Few 

rust  spots 

271 

1/10 

7.7283 

0.0032 

2 

" 

"          " 

272 

N 

7.9914 

0.0045 

2 

" 

"          " 

Table  XIX. — Sodium  Sulphate  with  N/10  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

272 

1/1000 

6.6671 

0.0001 

0 

274 

1/100 

6.2877 

0.0000 

0 

275 

1/10 

6.7019 

0.0067 

3 

276 

N 

8.4086 

0.0049 

2 

No 


Remarks, 
corrosion. 


Few  rust  spots. 


Table   XX. — Sodium    Sulphate   with   N/5   Potassium    Bichromate. 


Original         Loss  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

277 

1/1000 

6.9826 

0.0003 

278 

1/100 

6.9373 

0.0001 

279 

1/10 

6.9747 

0.0010 

280 

N 

6.7125 

0.0027 

Remarks. 


Cor'sion. 

0          No    corrosion. 
0 

0  •    " 

1  Few  rust  spots. 


COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 

Table  XXI. — Magnesium   Sulphate  with  N/1000  Potassium  Bichromate. 

Original         Loss  in     Relative 

on.  Remarks. 

Slight  rusting  on  edge 

Many  small  rust  spots. 
1  Gain    in    weight. 


No. 

Normality. 

Weight. 

Weight. 

Cor's 

33 

1/1000 

18.6374 

0.0011 

1 

34 

1/100 

17.7247 

0.0031 

2 

35 

1/10 

18.5333 

0.0080 

4 

36 

N 

18.8740 

0.0119 

6 

15 

Table  XXII. — Magnesium  Sulphate  with  N/100  Potassium  Bichromate. 
Original         Loss  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

37 

1/1000 

18.8471 

0.0002  ' 

0 

No  rust. 

38 

1/100 

18.7850 

0.0022 

1 

Several  black  spots. 

49 

1/10 

18.2635 

0.0107 

5 

Many  small  spots. 

40 

N 

18.1070 

0.0264 

13 

Covered  with  spots. 

Table 

XXIII.  —  Magnesium 

Sulphate 

with   N/10  Potassium  Bichromate 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

41 

1/1000 

18.6751 

0.0000 

0 

Metal  bright. 

42 

1/100 

18.7850 

0.0003  l 

0 

"          " 

43 

1/10 

18.7790 

0.0008 

1 

Minute  rust  spots. 

44 

N 

19.8571 

0.0280 

14 

Covered  with  spots. 

Table 

XXIV.  —  Magnesium 

Sulphate 

with  N/5  Potassium  Bichromate. 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

Original 

Loss  in 

Relative 

45 

1/1000 

19.1785 

0.0000 

0 

Metal  bright. 

46 

1/100 

19.5526 

0.0003  1 

0 

"           " 

47 

1/10 

19.9281 

0.0010 

1 

Few  minute  rust  spots. 

48 

N 

18.2517 

0.0238 

12 

Covered  with  rust  spots. 

LOW   CARBON   STEEL.     ROOM    TEMPERATURE. 
Table  XXV. — Magnesium  Sulphate  with  N/1000  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

281 

1/1000 

6.9384 

0.0038 

2 

282 

1/100 

7.0442 

0.0127 

6 

283 

1/10 

7.6038 

0.0073 

4 

284 

N 

7.6373 

0.0124 

6 

Remarks. 

Few  spots  over  surface. 
Many  small  spots. 
'Few  small  rust  spots. 
Many  small  spots. 


Table  XXVI. — Magnesium  Sulphate  with  N/100  Potassium  Bichromate. 

Original         Loss  in     Relative 

Cor'sion.  Remarks. 

0          No   corrosion. 
3          Few  rust  spots. 


No. 

Normality. 

Weight. 

Weight. 

285 

1/1000 

7.7890 

0.0000 

286 

1/100 

7.7853 

0.0050 

287 

1/10 

7.9115 

0.0094 

288 

N 

7.6104 

0.0218 

11 


Many  rust  spots. 


Table  XXVII. — Magnesium  Sulphate  with  N/10  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

FO. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

289 

1/1000 

7.5233 

0.0002 

0 

No  corrosion. 

290    - 

1/100 

7.8860 

0.0001 

0 

"            " 

291 

1/10 

8.1318 

0.0004 

0 

"            " 

292 

N 

7.6104 

0.0210 

11 

Covered   with  si 

1  Gain   in   weight. 


16 


Table  XXVIII. — Magnesium  Sulphate  with  N/5  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

293 

1/1000 

7.4765 

0.0002 

0 

Metal  bright. 

294 

1/100 

7.2624 

0.0002 

0 

«           « 

295 

1/10 

8.1285 

0.0007 

0 

No  corrosion. 

296 

N 

8.3027 

0.0241 

12 

Covered  with  rusty 

spots. 


COMMERCIALLY  PURE  IRON.     ROOM   TEMPERATURE. 


Table    XXIX.— Saturated    Solution    of    Calcium    Sulphate    (20°  C.), 


Original 

Loss  in 

Relative 

No. 

Normality.1 

Weight. 

Weight. 

Cor'sion. 

85 

1/1000 

18.3412 

0.0098 

5 

86 

1/100 

18.0028 

0.0007  - 

0 

87 

1/10 

18.7949 

0.0003  - 

0 

88 

1/5 

18.7370 

0.0002  - 

0 

Remarks. 

Several  large  streaks. 
Black  spots. 
No   corrosion. 


LOW   CARBON   STEEL.     ROOM   TEMPERATURE. 
Table   XXX.— Saturated   Solution   of   Calcium   Sulphate    (20°  C.). 


Original 

Loss  in 

Relative 

No. 

Normality.1 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

365 

1/1000 

8.0091 

0.0088 

4 

Minute  spots. 

366 

1/100 

7.7364 

0.0001 

0 

No  corrosion. 

367 

1/10 

7.1023 

0.0004 

0 

"            " 

368 

1/5 

7.4972 

0.0005 

0 

"            " 

COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 


Table  XXXI. — Sodium   Chloride  with   N/1000  Potassium  Bichromate. 


No. 

49 
50 
51 
52 

Table 

No. 
53 
54 
55 
56 

Original         Loss  in     Relative 
Normality.      Weight.         Weight.     Cor'sion. 
1/1000           18.2921           0.0452           23 
1/100           18.3231           0.0100              5 
1/10           18.5411           0.0122              6 
N           18.2830           0.0173              9 

XXXII.—  Sodium  Chloride  with  N/100 

Original         Loss  in     Relative 
Normality.     Weight.         Weight.    Cor'sion. 
1/1000           17.3569           0.0004  l           0 
1/100           17.7729           0.0021          .    1 
1/10           18.8033           0.0183              9 
N           18.1411           0.0329           17 

Remarks. 
Covered  with   rust. 
Narrow  long  black  streaks. 

Covered  with  thin  layer  of  rust. 
Potassium  Bichromate. 

Remarks. 
No  corrosion. 
Several  rust  spots. 
'Covered  with  thin  layer  of  rust 
Covered   with  rust  spots. 

1  Normality  of  potassium  dichromate. 
2  Gain   in   weight. 


17 
Table  XXXIII. — Sodium  Chloride  with  X/10  Potassium  Bichromate. 


No. 

57 
58 

Normality. 
1/1000 
1/100 

Original 
Weight. 
17.9824 
18.9423 

Loss  in 
Weight 
0.0004 
0.0003 

Relative 
.    Cor'sion. 
1          0 
1          0 

Remarks. 
No  corrosion. 

59 

1/10 

18.8458 

1.0307 

15 

Covered  with  layer  of  rust. 

60 

N 

18.7504 

0.0633 

32 

Table 

XXXIV.—  Sodium 

Chloride 

with  N/5 

Potassium  Bichromate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks. 

61 

1/1000 

17.5235 

0.0001 

1          0 

Metal 

bright. 

62 

1/100 

18.4591 

0.0004 

1          0 

" 

" 

63 

1/10 

17.9659 

0.0423 

21 

Many 

small  rust  spots. 

64 

N 

18.2212 

0.0530 

27 

Badly 

corroded. 

LOW   CARBON   STEEL.     ROOM   TEMPERATURE. 


Table   XXXV.— Sodium    Chloride    with    N/1000    Potassium    Bichromate. 


Original 

Loss  in     Relative 

No. 

Normality. 

Weight. 

Weight.    Cor'sion.              Remarks. 

297 

1/1000 

8.0472 

0.0374          19          Rust  spots  in  streaks. 

298 

1/100 

8.2619 

0.0185            9          Many  rust  spots. 

299 

1/10 

7.7362 

0.0156             8          Large  rust  spots. 

300 

N 

8.5746 

0.0190           10 

Table 

XXXVI.—  Sodium    Chloride    with    N/100    Potassium    Bichromate. 

Original 

Loss  in     Relative 

No. 

Normality. 

Weight. 

Weight.    Cor'sion.              Remarks. 

301 

1/1000 

8.6156 

0.0001             0          No  corrosion. 

302 

1/100 

7.5995 

0.0002             0          Several   minute  spots. 

303 

1/10 

8.5122 

0.0174             9           Many  small   rust  spots. 

304 

N 

8.1990 

0.0375          19          Covered  with  large  rust  spots. 

Table 

XXXVII.—  Sodium 

Chloride  with  N/10  Potassium  Bichromate. 

Original 

Loss  in     Relative 

No. 

Normality. 

Weight. 

Weight.     Cor'sion.               Remarks. 

305 

1/1000 

8.4199 

0.0007             0          No  corrosion. 

306 

1/100 

8.5453 

0.0016             1          Few  minute  rust  spots. 

307 

1/10 

7.9314 

0.0336           17          Covered   with  small  spots. 

308 

N 

8.7001 

0.0652           33 

Table 

XXXVIII.- 

—  Sodium 

Chloride  with  N/5  Potassium  Bichromate. 

Original 

Loss  in     Relative 

No. 

Normality. 

Weight. 

Weight.    Cor'sion.              Remarks. 

309 

1/1000 

8.0314 

0.0005             0          No  corrosion. 

310 

1/100 

6.6100 

0.0035             2          Few  minute  spots. 

311 

1/10 

7.5867 

0.0409           20          Many  large  rust  spots. 

312 

N 

8.1445 

0.0515           26 

1  Gain    in    weight. 

18 


COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 


Table   XXXIX.— Magnesium   Chloride   with    N/1000   Potassium   Bichromate. 


Remarks. 

Corrosion  on  edges. 
Few  minute  rust  spots. 
Covered      with     minute     rust 

spots. 
Many  small  rust  spots. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

65 

1/1000 

17.5235 

0.0018 

1 

66 

1/100 

18.4563 

0.0024 

1 

67 

1/10 

18.6983 

0.0164 

8 

68 


N 


18.8969 


0.0128 


Table  XL. — Magnesium  Chloride  with  N/100  Potassium  Bichromate. 


Original 

Loss  in 

No. 

Normality. 

Weight. 

Weight. 

69 

1/1000 

17.0475 

0.0002 

70 

1/100 

17.3322 

0.0009  ' 

71 

1/10 

17.3590 

0.0151 

72 

N 

17.8621 

0.0246 

Relative 

Cor'sion.  Remarks. 

0          Several   minute  spots. 

0          No  corrosion. 

8          Covered  with  thin  layer  ru.st. 
12  "  


Table  XLI. — Magnesium  Chloride  with  N/10  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

'Cor'sion. 

Remarks. 

73 

1/1000 

19.5877 

0.0004  * 

0 

Metal  bright. 

74 

1/100 

18.1777 

0.00031 

0 

"          " 

75 

1/10 

18.0645 

0.0209 

10 

Covered     with 

rust  spots. 

76 


X 


18.1682 


0.0528 


26 


small     lumpy 


Table  XLII. — Magnesium  Chloride  with  N/5  Potassium  Bichromate. 


No.  Normality. 

77  1/1000 

78  1/100 
19  1/10 

80  N 


Original  Loss  in  Relative 

Weight.  Weight.  Cor'sion.               Remarks. 

18.9682  0.0004  l  0           Metal    bright. 

17.4384  0.0002  1  0 

18.3128  0.0212  11          Covered     with     small 

spots. 

17.9440  0.0540  27 


lumpy 


LOW   CARBON   STEEL.     ROOM   TEMPERATURE. 
Table  XLIII. — Magnesium  Chloride  with  N/1000  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

313 

1/1000 

8.7930 

0.0020 

1 

Few  rust  spots. 

314 

1/100 

8.4156 

0.0038 

2 

"         "          " 

315 

1/10 

8.5263 

0.0143 

7 

Rust  around  edges. 

316 

N 

7.4669 

0.0160 

8 

Many  minute  spots. 

1  Gain   in   weight. 


19 
Table  XLIV. — Magnesium   Chloride  with   N/100  Potassium   Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    'Cor'sion. 

Remarks. 

317 

1/1000 

8.7930 

0.0020 

1 

Minute    spots. 

318 

1/100 

8.3371 

0.0057 

3 

Several    large    black 

spots 

319 

1/10 

7.7715 

0.1042 

7 

Covered  with  minute 

spots. 

320 

N 

8.2331 

0.0550 

27 

" 

*' 

Table 

XLV.  —  Magnesium 

Chloride 

with  N/10  Potassium  Bichromate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks. 

321 

1/1000 

7.7367 

0.0004 

0 

No  corrosion. 

322 

1/100 

8.0481 

0.0004 

0 

"            " 

323 

1/10 

8.0177 

0.0193 

10 

Covered  with  spots. 

324 

N 

8.5306 

0.0632 

31 

Badly  corroded. 

Table 

XLVI.  —  Magnesium 

Chloride 

with   N/5  Potassium  Bichromate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks. 

325 

1/1000 

7.9113 

0.0003 

0 

No   corrosion. 

326 

1/100 

8.1286 

0.0001 

0 

"            " 

327 

1/10 

7.9591 

0.0259 

13 

Covered  with  rust  spots. 

328 

N 

8.3227 

0.0756 

38 

Badly    corroded. 

SUMMARY   OF   RESULTS.     ROOM   TEMPERATURE. 


Solutions   of    Sodium    Sulphate    and    Potassium    Bichromate. 

1.  The  differences  in  chemical  composition  and  physical  properties  had 
no  influence  upon  the  rate  of  corrosion. 

2.  Only  the  solutions  which  contained  very  dilute  amounts  of  potassium 
dichromate  showed  any  marked  corrosion. 

3.  N/10   arid   N/5   potassium   dichromate   rendered   the   iron    and   steel 
passive  in  the  more  dilute  solutions  of  the  sodium  sulphate.1 

4.  In    all    other    cases    the    potassium    dichromate    decidedly    inhibited 
corrosion. 

Solutions   of   Magnesium    Sulphate   and   Potassium   Bichromate. 

1.  The  differences  in  chemical  composition  and  physical  properties  of 
the  iron  and  steel  had  no  influence  upon  the  rate  of  corrosion. 

2.  Tenth    normal    and    normal    solutions    of    magnesium    sulphate    con- 
taining  potassium   dichromate   in   all  proportions   used,    were   covered   with 
rustf  spots  of  varying  sizes.     While  this  was  generally  true  in  the  case  of 
sodium  sulphate  solutions,  the  rate  of  corrosion  with  the  magnesium  sulphate 
solutions  was  much   greater. 


1  The    passivification    of   the    test-plates    was    determined    by    dipping    them    into    nitric 
acid    of   1.20    specific   gravity. 


20 

3.  N/10   and   N/5   potassium   dichrornate    passivified   the   test-plates   of 
both  iron  and  steel  in  N/100  magnesium  sulphate.     This  was  also  true  with 
N/5  potassium  dichromate  in  N/100  magnesium  sulphate.     With  the  latter 
solution  containing  N/10  potassium  dichromate,  the  passive  state  was  dem- 
onstrated twice  with  four  test-plates  of  iron  and  twice  with  three  test-plates 
of  the  steel.     To  determine  the  passive  state   of  the  iron  and  steel,   other 
plates  than  those  used  to  secure  the  loss  in  weight  were  run  under  identical 
conditions.     At  the  end  of  two  weeks  they  were  washed  carefully,  and  then 
immersed  in  the  nitric  acid  of  1.20  sp.  gr. 

4.  In  all  cases  potassium  dichromate  inhibited  corrosion  to  a  marked 
extent. 

Saturated  Solution  of  Calcium  Sulphate  (20°  C.)  and  Potassium  Dichromate. 

1.  With  the  exception  of  N/1000  potassium  dichromate,  the  addition 
of  this  salt  to  the  saturated  solution  of  calcium  sulphate  produced  results 
similar  to  those  obtained  in  solutions  containing  only  the  dichromate. 

Solutions   of  Sodium   Chloride   and   Potassium   Dichromate. 

1.  There  was  no  difference  in  the  behavior  of  the  iron  and  steel. 

2.  The  most  peculiar  action  was  obtained  with  N/1000  solution  of  both 
the  sodium  chloride  and  potassium  dichromate.     With  this  solution  the  rate 
of   corrosion   was  many  times   higher   than   that   obtained   with   magnesium 
chloride  or  with  the  sulphate  solutions.     With  the  iron,  four  tests   gave  a 
loss  in  weight  of  0.0452,  0.0397,   0.0190,   and  0.0432   gram. 

3.  The    passive    state    was    demonstrated   in   many   cases    with    N/1000 
and  N/100  sodium  chloride  containing  N/10  and  N/5  potassium  dichromate. 

4.  The    inhibiting    action    of    the    dichromate    is    less    in    the    sodium 
chloride    solutions   than   in    the    corresponding   sulphate   solutions. 

Solutions    of   Magnesium    Chloride   and   Potassium   Dichromate. 

1.  The  behavior  of  the  iron  and  steel  appears  to  be  the  same  in  many 
cases. 

2.  Test-plates  were  passivified  in  N/1000  and  N/100  solutions  of  the 
chloride  with  N/10  and  N/5  potassium  dichromate. 

3.  In  the  more   concentrated  solutions  of  the   chloride,  an  increase  in 
either  salt  produced   an  increase   in   corrosion. 

4.  The   inhibiting  action   of  the  potassium   dichromate  is  less  than  in 
the  corresponding  sulphate  solutions. 

5.  The  action  of  many  of  the  magnesium  chloride  solutions  were  sim- 
ilar to  those  of  sodium  chloride.     Normal  solutions  of  the  former,  however, 
were  exceptions,   corrosion  being  much   greater. 


21 


ACTION    OF    SOLUTIONS    OF    CHLORIDES    AND    SULPHATES    UPON 

IRON  AND  STEEL  AT  THE  TEMPERATURE  OF  BOILING  WATER 

IN  THE  PRESENCE  OF  POTASSIUM  DICHROMATE. 

In  the  tests  run  at  room  temperature  potassium  dichromate  reduced 
corrosion  to  a  marked  extent  in  every  case,  in  some  instances  preventing 
all  chemical  action  upon  the  iron  and  steel.  Thus  tanks  used  for  storing 
non-potable  waters  at  atmospheric  temperatures  could  be  well  preserved  by 
the  addition  of  small  quantities  of  potassium  dichromate.  However,  with 
waters  in  boilers  the  addition  of  this*  compound  will,  in  many  cases,  serve 
as  a  stimulative  agent  rather  than  as  a  preventive  for  corrosion.  This  will 
be  seen  by  studying  the  data  obtained  when  the  iron  and  steel  were  placed 
in  solutions  free  from  dichromate  at  boiling  temperature  for  two  weeks  and 
comparing  them  with  the  results  from  those  boiled  in  solutions  in  which  this 
salt'  was  present.  In  many  of  the  solutions  the  presence  of  the  dichromate 
was  occasioned  by  a  slight  increase  in  corrosion.  This  was  especially  true 
in  the  chloride  solutions.  In  fact,  from  the  general  appearances  of  the  test- 
plates,  this  increase  in  corrosion  seemed  greater  than  that  actually  repre- 
sented by  the  following  figures. 

Plates  of  the  iron  and  steel  were  introduced  into  distilled  water  and 

subjected  to  the  same  treatment  as  accorded  to  the  samples  in  the  various 

;  solutions.     At  the  end  of  two  weeks  the  plates  were  removed,   dried,  and 

weighed.     The  plates  were  all  slightly  tarnished.     The  gain  in  weight  of  the 

plates  served  as  a  standard  for  calculating  the  relative   corrosion. 

The  test-plates  immersed  in  the  salt  solutions  free  from  dichromate 
corroded  to  a  certain  extent,  a  small  brown  precipitate  settling  on  the 
bottom  of  the  containing  vessel.  It  was  thus  impossible  to  weigh  the  plates 
directly  and  determine  the  rate  of  corrosion  by  gain  in  weight.  The  plates, 
however,  were  very  easily  cleaned  with  ammonium  citrate  and  the  loss  in 
weight  determined.  The  equivalent  amount  of  ferric  oxide  represented  by 
the  loss  in  weight  was  calculated.  While  this  does  not  accurately  represent 
the  actual  amount  of  corrosive  matter  produced  it  is  fairly  approximate,  so 
that  it  can  be  reasonably  compared  with  the  data  obtained  from  plates 
where  cleaning  was  impossible. 

N/5  dichromate  produced  a  decrease  in  the  rate  of  corrosion  in  nearly 
every  case.  In  some  instances,  especially  with  solutions  of  sodium  sulphate 
containing  N/10  dichromate,  there  is  a  decided  increase  in  corrosion,  while 
in  others  the  dichromate  appears  to  have  little  or  no  effect.  In  general  the 
addition  of  dichromate  to  boiler  waters  would  be  of  no  practical  use,  as  an 
alteration  in  the  concentrations  of  the  salts  would  produce  a  difference  in 
action.  This  would  be  especially  true  if  chlorides  were  present.  Under  such 
circumstances  the  effect  of  the  sulphates  would  be  acted  upon  by  the 
chlorides  and  the  final  result  would  be  a  stimulation  of  corrosion. 

The  presence  of  dichromate  in  solutions  of  the  chlorides  caused  a 
decided  increase  in  the  rate  of  corrosion,  the  magnesium  chloride  being 
more  violent  in  its  behavior  than  the  sodium  chloride.  Chemical  interaction 


22 

undoubtedly  takes  place  between  the  chlorides,  potassium  dichromate,  and 
water,  with  the  production  of  small  amounts  of  hydrochloric  acid,  thus 
causing  the  great  increase  in  corrosive  action.  Friend  '  has  suggested  the 
following  chemical  equation  to  show  the  production  of  the  hydrochloric  acid  : 


2NaCl+K2Cr2O+  H*0 


h  K.Cr  0*+2 


Because  of  experimental  difficulties  the  results  reported  for  the  action  of 
the  stronger  solutions  of  the  chlorides  with  N/10  and  N/5  dichromate  upon 
the  iron  and  steel  are  low  : 


COMMERCIALLY  PURE  IRON.     TEMPERATURE  OF  BOILING  WATER. 


Table   XLVIL— Action   of  Water. 


No. 
A 
B 
C 
D 
E 


Original 
Weight. 
19.1064 

18.8200 
18.8349 
19.1126 
18.7442 


Gain  in 

Weight. 

0.0055 

0.0048 

0.0043 

0.0063 

0.0057 


Remarks. 
Tarnished. 


Table  XL VIII. — Potassium  Dichromate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

189 

1/1000 

19.1515 

0.0023 



190 

1/100 

19.7182 

0.0015 



191 

1/10 

18.2635 

0.0013 

— 

192 

1/5 

19.6910 

0.0010 

-- 

Remarks. 
Tarnished 
Slightly  tarnished. 


LOW  CARBON  STEEL.     TEMPERATURE   OF   BOILING  WATER. 


No. 
A 

B 
C 
D 


Table  XLXIX.— Action  of  Water. 


Original 
Weight. 
7.0429 
7.0774 
7.4627 
6.9830 


Gain  in 

Weight. 

0.0074 

0.0074 

0.0081 

0.0090 


Remarks. 
Minute  spots. 


Table    L. — Potassium    Dichromate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

445 

1/1000 

6.2030 

0.0017 



446 

1/100 

7.4011 

0.0007 

— 

447 

1/10 

6.6794 

O.OOlo 



448 

1/5 

7.0553 

0.0015 

__ 

Remarks. 
Slightly  tarnished. 


23 
COMMERCIALLY  PURE  IRON.    TEMPERATURE  OF  BOILING  WATER. 


Table  LI. — Sodium  Sulphate. 


No. 

Normality. 

Original 
Weight. 

Loss  in 
Weight. 

Loss  as 
Ferric 
Oxide.              E 

193 
194 
195 
196 

1/1000 
1/100 
1/10 

N 

19.2936 
18.6913 
18.4841 
16.6731 

0.0039 
0.0043 
0.0057 
0.0062 

0.0056 
0.0061 
0.0081 
0.0089 

Table  LII.  —  Magnesium  Sulphate. 

No. 

Normality. 

Original 
Weight. 

'Loss  in 
Weight. 

Loss  as 
Ferric 
Oxide.               F 

197 
198 
199 
200 

1/1000 
1/100 
1/10 

N 

17.4416 
19.6567 

18.6475 
18.9933 

0.0043 
0.0049 
0.0062 
0.0071 

0.0061 
0.0070 
0.0089 
0.0101 

Table 

LIII.  —  Sodium  Chloride. 

No. 

Normality. 

Original 
Weight. 

Loss  in 
Weight. 

Loss  as 
Ferric 
Oxide.              I 

201 
202 
203 
204 

1/1000 
1/100 
1/10 

N 

18.8491 
16.3931 
17.9781 
16.9963 

0.0043 
0.0051 
0.0063 
0.0054 

0.0061 
0.0073 
0.0090 
0.0077 

Table    LIV.  —  Magnesium    Chloride. 

No. 

Normality. 

Original 
Weight. 

Loss  in 
Weight. 

Loss  as 
Ferric 
Oxide.              I 

205 
206 
207 
208 

1/1000 
1/100 
1/10 

N 

17.7218 
18.4160 
18.5508 
17.0679 

0.0049 
0.0058 
0.0096 
0.0107 

0.0070 
0.0083 
0.0137 
0.0153 

Remarks. 


Remarks. 


Remarks. 


Remarks. 


LOW  CARBON  STEEL.    TEMPERATURE  OF  BOILING  WATER. 


Table   LV.— Sodium   Sulphate. 


Loss  as 

t 

Original 

'Loss  in 

Ferric 

No. 

Normality. 

Weight. 

Weight. 

Oxide. 

377 

1/1000 

6.5609 

0.0063 

0.0090 

378 

1/100 

6.0070 

0.0061 

0.0088 

379 

1/10 

7.6734 

0.0066 

0.0094 

380 

N 

7.1523 

0.0067 

0.0096 

Remarks. 


24 


Table  LVI. — Magnesium   Sulphate. 


Original         Loss  in 

No. 

Normality. 

Weight.         Weight. 

381 

1/1000 

6.3835           0.0058 

382 

1/100 

6.7226           0.0058 

383 

1/10 

6.8952           0.0063 

384 

N 

7.2419           0.0071 

Table   LVIL—  Soc 

Original         Loss  in 

No. 

Normality. 

Weight.         Weight. 

385 

1/1000 

6.3420           0.0054 

386 

1/100 

7.4483           0.0062 

387 

1/10 

7.2679           0.0068 

388 

N 

6.7082           0.0059 

Table   LVIIL—  Mag: 

Original         Loss  in 

No. 

Normality. 

Weight.         Weight. 

389 

1/1000 

6.7509           0.0062 

390 

1/100 

7.1248           0.0068 

391 

1/10 

7.5381           0.0092 

392 

N 

7.0032           0.0118 

Remarks. 


Chloride. 


Loss  as 
Ferric 
Oxide. 

0.0077 
0.0089 
0.0097 
0.0084 


Loss  as 

Ferric 

Oxide. 

0.0089 

0.0097 

0.0131 

0.0169 


Remarks. 


Remarks. 


COMMERCIALLY  PURE  IRON.    TEMPERATURE  OF  BOILING  WATER. 


Table  LIX. — Sodium  Sulphate  with  N/1000  Potassium  Bichromate. 


Original 
No.        Normality.     Weight. 

121  1/1000     18.2543 

122  1/100     17.9236 

123  1/10     18.0497 

124  N     18.5067 


Gain  in  Relative 

Weight.  Cor'sion.              Remarks. 

0.0081  155  Few  streaks  and  spots. 

0.0052  100 

0.0042  79  Several  spots. 

0.0057  107  Few  spots. 


Table    LX. — Sodium    Sulphate    with    N/100    Potassium    Bichromate. 


No. 
125 
126 
127 
128 

Table 

No. 
129 
130 
131 
132 

Original         Gain  in     Relative 
Normality.     Weight.         Weight.    'Cor'sion. 
1/1000           18.2348           0.0038              71 
1/100           19.5568           0.0049              92 
1/10           18.7812           0.0060           113 
N          18.0550           0.0076           143 

LXL—  Sodium    Sulphate    with    N/10 

Original         Gain  in      Relative 
Normality.     Weight.         Weight.    Cor'sion. 
1/1000           18.9583           0.0036              68 
1/1-00           18.7540           0.0086           162 
1/10           19.6902           0.0158           299 
N           18.8220           0.0077           145 

Remarks. 
No  corrosion.     Tarnished. 
Few  spots. 
Streaks  and  spots. 

Potassium    Bichromate. 

Remarks. 
No  corrosion. 
Well  tarnished. 
Few  rust  spots. 
Few  streaks. 

25 


Table    LXII. — Sodium    Sulphate    with    N/5    Potassium    Bichromate. 


Original         Gain  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion 

133 

1/1000 

18.1663 

0.0033 

62 

134 

1/100 

19.1555 

0.0033 

62 

135 

1/10 

18.0014 

0.0120 

226 

136 

N 

18.0851 

0.0124 

234 

No 


Remarks, 
corrosion. 


Few  spots  and  streaks. 


LOW  CARBON  STEEL.    TEMPERATURE  OF  BOILING  WATER. 
{Table    LXIII.— Sodium    Sulphate    with    N/1000    Potassium    Bichromate. 


No. 
393 
394 
395 
396 


Original         Gain  in      Relative 


Normality. 
1/1000 

Weight. 
7.8221 

Weight. 
0.0067 

Cor'sion. 

84 

1/100 
1/10 

N 

8.7803 
9.1039 
8.9027 

0.0073 
0.0095 
0.0086 

91 
119 

108 

Remarks. 
Few  streaks  and  spots. 

Many  minute  spots. 
'Few  spots  and  streaks. 


Table  LXIV. — Sodium  Sulphate  with  N/100  Potassium  Bichromate. 


No.  Normality. 

397  1/1000 

398  1/100 

399  1/10 

400  N 


Original 

Gain  in 

Relative 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

8.2508 

0.0057 

71 

Few  spots. 

7.5331 

0.0058 

73 

"        " 

8.2940 

0.0098 

123 

Streaks  and  spots. 

8.7572 

0.0095 

119 

"          "        " 

Table   LXV. — Sodium    Sulphate   with    N/10   Potassium   Bichromate. 


Original         Gain  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

401 

1/1000 

8.9566 

0.0037 

46 

402 

1/100 

9.1438 

0.0091 

114 

403 

1/10 

9.0236 

0.0124 

155 

404 

N 

9.0028 

0.0119 

149 

Remarks. 
No  corrosion. 

"  Tarnished 

Few  spots  and  streaks. 


Table    LXVI. — Sodium    Sulphate   with    N/5    Potassium    Bichromate. 


Remarks. 
No    corrosion.      Tarnished. 

Few    rust    spots. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

405 

1/1000 

9.1142 

0.0043 

54 

406 

1/100 

9.2546 

0.0032 

40 

407 

1/10 

8.7928 

0.0114 

143 

408 

N 

8.2371 

0.0097 

121 

COMMERCIALLY  PURE  IRON.    TEMPERATURE  OF  BOILING  WATER. 
Table    LXVII. — Magnesium    Sulphate    with    N/1000    Potassium    Bichromate. 


Remarks. 
Few  spots. 

'Black   spots   and   streaks. 
Black  streaks. 


4 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight 

Weight. 

Cor'sion. 

137 

1/1000 

19.1782 

0.0048 

91 

138 

1/100 

19.2714 

0.0101 

191 

139 

1/10 

18.2537 

0.0077 

145 

140 

N 

18.5238 

0.0110 

208 

26 

Table    LXVIII. — Magnesium    Sulphate    with    N/100    Potassium    Bichromate. 
Original         Gain  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

141 

1/1000 

19.1782 

0.0046 

87 

Dull  in  color. 

142 

1/100 

18.7740 

0.0073 

138 

Spots  over  surface. 

143 

1/10 

18.7936 

0.0097 

183 

«          «<            « 

144 

N 

18.9597 

0.0126 

238 

n          tt            a 

Table 

LXIX.  —  Magnesium 

Sulphate 

with    N/10 

Potassium   Dichromat'e 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

145 

1/1000 

17.1741 

0.0006 

11 

Slightly  tarnished. 

146 

1/100 

17.8488 

0.0013 

23 

"              " 

147 

1/10 

18.3274 

0.0086 

162 

Few  small  spots. 

148 

N 

18.3712 

0.0106 

200 

Table 

LXX.  —  Magnesium 

Sulphate 

with  N/5 

Potassium   Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

149 

1/1000 

18.5256 

0.0003 

6 

No  corrosion. 

150 

1/100 

18.1176 

0.0011 

21 

Slightly  tarnished. 

151 

1/10 

19.6333 

0.0065 

123 

Spots  and  streaks. 

152 

N 

18.8247 

0.0082 

151 

"        "          " 

LOW  CARBON  STEEL.    TEMPERATURE  OF  BOILING  WATER. 
Table  LXXI. — Magnesium  Sulphate  with  N/1000  Potassium  Bichromate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

409 

1/1000 

8.3184 

0.0037 

46 

Black  spots  and  streaks. 

410 

1/100 

7.0408 

0.0160 

200 

Many  spots. 

411 

1/10 

7.9015 

0.0097 

121 

Spots  and  streaks. 

412 

N 

7.1737 

0.0115 

144 

"        *  *           *  ' 

Table 

LXXII.  —  Magnesium 

Sulphate 

with  N/100  Potassium  Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

413 

1/1000 

8.1879 

0.0042 

53 

Few  black  spots. 

414 

1/100 

9.2314 

0.0118 

148 

Many  small  spots. 

415 

1/10 

7.9020 

0.0088 

110 

Spots  over  surface. 

416 

N 

7.1787 

0.0108 

145 

'Many  small  spots. 

Table 

LXXIII.  —  Magnesium 

Sulphate 

with  N/10  Potassium  Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

417 

1/1000 

7.8221 

0.0010 

13 

Slightly  tarnished. 

418 

1/100 

8.0716 

0.0013 

16 

"               " 

419 

1/10 

8.8831 

0.0085 

106 

'Few  spots  over  surface. 

420 

N 

7.8375 

0.0100 

125 

Many  small   spots. 

27 


Table  LXXIV. — Magnesium  Sulphate   with  N/5  Potassium  Bichromate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

421 

1/1000 

7.2037 

0.0014 

18 

422 

1/100 

9.1524 

0.0009 

11 

423 

1/10 

8.2165 

0.0057 

71 

424 

N 

8.5532 

0.0095 

119 

Remarks. 
Slightly    tarnished. 

Few    small    spots. 
Spots  and  streaks. 


COMMERCIALLY  PURE  IRON.    TEMPERATURE  OF  BOILING  WATER. 
Table  LXXV. — Sodium  Chloride  with  N/1000  Potassium  Bichromate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

153 

1/1000 

18.1790 

0.0075 

141 

Few  black  spots. 

154 

1/100 

18.6186 

0.0069 

130 

n          a           « 

155 

1/10 

18.2633 

0.0066 

124 

"          "           " 

156 

N 

18.9162 

0.0062 

117 

Table 

LXXVL—  Sodium  Chloride  with  N/100 

Potassium  Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

157 

1/1000 

18.9220 

0.0120 

226 

Few  black  spots. 

158 

1/100 

18.1262 

0.0208 

392 

Spots   over  surface. 

159 

1/10 

17.6083 

0.0267 

504 

Many  small  spots. 

160 

N 

17.2738 

0.0210 

396 

Table 

LXXVII.—  Sodium 

Chloride 

with  N/10 

Potassium  Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

161 

1/1000 

18.2339 

0.0011 

20    ' 

Tarnished  slightly. 

162 

1/100 

19.3364 

0.0048 

91 

Well   tarnished. 

163 

1/10 

18.2891 

0.0282 

532 

Many  small  spots. 

164 

N 

18.7213 

0.0447 

843 

Covered  with  rust. 

Table 

LXXVIII 

.  —  Sodium 

Chloride 

with   N/5 

Potassium  Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

,    Cor'sion. 

Remarks. 

165 

1/1000 

19.2181 

0.0018 

34 

Slightly  tarnished. 

166 

1/100 

19.7539 

0.0078 

147 

Few   spots. 

167 

1/10 

18.9736 

0.0262 

494 

Many  small  spots. 

168 

N 

19.3316 

0.0453 

855 

Covered  with  rust. 

LOW  CARBON  STEEL.    TEMPERATURE  OF  BOILING  WATER, 
Table   LXXIX.— Sodium   Chloride   with  •  N/1000   Potassium   Bichromate. 


Original         Gain  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

425 

.      1/1000 

8.6269 

0.0065 

81 

426 

1/100 

7.4392 

0.0095 

119 

427 

1/10 

7.7890 

0.0082 

102 

428 

N 

7.5234 

0.0052 

65 

Remarks. 
Few  small  spots. 
Many  small  spots. 
Several  streaks  and  spots. 


28 
Table   LXXX.— Sodium    Chloride   with   N/100  Potassium   Bichromate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

429 

1/1000 

8.8366 

0.0139 

174 

Many  minute  spots. 

430 

1/100 

7.6972 

0.0134 

168 

"            "          " 

431 

1/10 

8.1314 

0.0167 

209 

Streaks  and  spots. 

432 

N 

8.1278 

0.0190 

238 

a           «          tt 

Table 

LXXXI.- 

-Sodium 

Chloride   with    N/10 

Potassium   Bichromate, 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

433 

1/1000 

7.6622 

0.0013 

16 

Slightly  tarnished. 

434 

1/100 

7.6972 

0.0052 

65 

Few   spots. 

435 

1/10 

7.8208 

0.0254 

318 

Many  minute  spots. 

436 

N 

8.7049 

0.0434 

543 

Badly  corroded. 

Table 

LXXXIL—  Sodium 

Chloride 

with  N/5 

Potassium  Bichromate. 

Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

437 

1/1000 

7.5060 

0.0014 

18 

Slightly  tarnished. 

438 

1/100 

7.3744 

0.0093 

116 

(Pew  minute  spots. 

439 

1/10 

7.6206 

0.0254 

318 

Covered  with  spots. 

440 

N 

7.7049 

0.0468 

585 

Badly  corroded. 

COMMERCIALLY  PURE  IRON.     TEMPERATURE  OF  BOILING  WATER 


Table  LXXXIII. — Magnesium  Chloride  with  N/1000  Potassium  Bichromate. 


Remarks. 

Spots  and  streaks. 
Many  small  spots. 
Streaks  and  spots. 


Original 

Gain  in 

Relative 

wo. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

ley 

1/1000 

18.6425 

0.0091 

173 

170 

1/100 

19.0886 

0.0116 

219 

171 

1/10 

19.7181 

0.0132 

249 

172 


N 


18.0293 


0.0231 


436 


Table   LXXXIV. — Magnesium   Chloride   with   N/100   Potassium   Bichromate. 


Remarks. 

Few  minute  spots. 
Many  spots. 
Badly    corroded. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

173 

1/1000 

19.1877 

0.0057 

108 

174 

1/100 

18.9242 

0.0149 

281 

175 

1/10 

18.6621 

0.0229 

432 

176 


N 


18.4985 


0.0321 


606 


LXXXV. — Magnesium   Chloride   with   N/10   Potassium   Bichromate. 


Remarks. 
Tarnished. 
Well    tarnished. 
Many  spots  and  streaks. 
Badly  corroded. 


WO. 

Normality. 

Original 
Weight. 

Gain  in 
Weight. 

Relative 
Cor'sion. 

177 
178 
179 

1/1000 
1/100 
1/10 

17.9358 
19.4608 
18.3315 

0.0010 
0.0014 
0.0289 

19 
26 
545 

180 


N 


18.9670 


0.0479 


903 


Table  LXXXVI. — Magnesium  Chloride  with  N/5  Potassium  Bichromate. 


No.  Normality. 

181  1/1000 

182  1/100 

183  1/10 

184  N 


Original 
Weight. 
18.4936 
19.4126 
18.3315 
19.1092 


Gain  in 
Weight. 
0.0011 
0.0011 
0.0321 
0.0744 


•Relative 

Cor'sion. 

20 

20 

606 

140 


Remarks. 
Slightly  tarnished. 

Many  spots  and  streaks. 
Badly  corroded. 


LOW  CARBON  STEEL.     TEMPERATURE  OF  BOILING  WATER. 
Table  LXXXVII. — Magnesium  Chloride  with  N/1000  Potassium  Bichromate. 


No.  Normality. 

465  1/1000 

466  1/100 

467  1/10 

468  N 


Original  Gain  in  Relative 

Weight.  Weight.  Cor'sion. 

7.2108  0.0122  153 

6.9734  0.0122  153 

7.0399  0.0180  225 

8.0032  0.0227  284 


Remarks. 

Many  small  spots. 
Streaks  and  spots. 

Many  spots  and  streaks. 


Table  LXXXVIII.— Magnesium  Chloride  with  N/100  Potassium  Bichromate. 


No.  Normality 

469  1/1000 

470  1/100 

471  1/10 

472  N 


Original         Gain  in     Relative 


Weight. 

Weight. 

(Jor  sion. 

6.8296 

0.0045 

56 

7.1818 

0.0163 

204 

7.1590 

0.0193 

241 

7.9684 

0.0237 

284 

Remarks. 
Few  spots. 
Many   minute   spots. 
Streaks  and  spots. 
Covered  with  rust. 


Table    LXXXIX. — Magnesium    Chloride    with    N/10    Potassium    Bichromate. 


No.  Normality. 

473  1/1000 

474  1/100 

475  1/10 

476  N 


Original 
Weight. 
7.3246 
7.7206 
8.0416 
7.3858 


Gam  in 
Weight. 
0.0020 
0.0015 
0.0282 
0.0459 


'Relative 

Cor'sion. 

25 

19 

353 

574 


Remarks. 
Slightly    tarnished. 

Covered  with  spots. 
Badly  corroded. 


Table   XC. — Magnesium   Chloride   with   N/5  Potassium   Bichromate. 


No.  Normality. 

477  1/1000 

478  1/100 

479  1/10 

480  N 


Original 
Weight. 

Gain  in 
Weight. 

'Relative 
Cor'sion. 

7.2677 

0.0005 

6 

6.7138 

0.0019 

24 

8.3392 

0.0419 

524 

7.3858 

0.0879 

1099 

Remarks. 

Slightly  tarnished. 
Tarnished. 
Badly  corroded. 


SUMMARY    OF    RESULTS.     (TEMPERATURE    OF    BOILING    WATER.) 

Solutions  of  Sodium  Sulphate  with  Potassium  Bichromate. 
• 

1.  With  very  dilute  solutions  of  the  sulphate  the  addition  of  dichromate 
causes  a  slight  inhibition  in  corrosion. 

2.  In  the  more  concentrated  solution  the  addition  of  dichromate  stim- 
ulates   corrosion. 


30 

3.  In  many  cases  the  corrosion  of  the  test-plates  appeared  to  be  greater 
in  comparison  with  those  in  solutions  free  from  dichromate  than  is  actually 
represented  by  the  gain  in  weight. 

4.  Generally  the  low  carbon  steel  was  more  easily  attacked  than  the 
commercially  pure  iron. 


Solutions  of  Magnesium  Sulphate  with  Potassium  Dichromate. 

1.  With  the  exception  of  N/1000  magnesium  sulphate  the  addition  of 
dichromate  in  small  amounts  stimulated  corrosion. 

2.  N/10  and  N/5  dichromate  inhibited  corrosion  in  varying  degrees. 

3.  Generally  the  low  carbon  steel  was  more  easily  attacked  than  the 
commercially  pure  iron. 

4.  The  action  of  the  magnesium  sulphate  solutions  were  less  than  those 
of  sodium  sulphate. 


Solutions   of   Sodium   Chloride   with   Potassium   Dichromate. 

1.  N/1000  dichromate  had  practically  no  effect  upon  the  corrosion  of 
the  plates,  although  there  was  a  general  tendency  towards  inhibition. 

2.  N/100  dichromate  stimulated  corrosion  in   every  case. 

3.  With   the  more  dilute  solutions  of  sodium  chloride,   N/10  and  N/5 
dichromate  inhibited  corrosion. 

4.  N/10   and   N/5   dichromate   in    the    more    concentrated   solutions    of 
sodium  chloride  stimulated  corrosion  to  a  marked  extent. 

5.  Commercially  pure   iron  showed  a  slightly   greater  increase   in  the 
rate  of  corrosion  than  did  the  low  carbon  steel. 

6.  Sodium    chloride    and   potassium   dichromate    interacted   with   water 
to  produce  traces  of  hydrochloric  acid. 

Solutions    of    Magnesium    Chloride    with    Potassium    Dichromate. 

1.  In   all  cases  the   action  of  these  solutions  upon  the  iron   and   steel 
was  greater  than  the  corresponding  solutions  of  sodium  chloride. 

2.  N/10    and    N/5    dichromate    in    the    dilute    solutions    of    magnesium 
chloride  inhibited  corrosion. 

3.  In    all    other    solutions    increase    in    either    the    dichromate    or    the 
chloride  produced  conditions  that  strongly  stimulated  corrosion. 

4.  Magnesium  chloride  and  potassium  dichromate  interact  with  water 
to  produce  hydrochloric  acid. 


31 

ACTION  OF  DI-SODIUM  PHOSPHATE  IN  THE  PRESENCE  OF  SODIUM 
SULPHATE  AND  SODIUM  CHLORIDE. 

When  an  iron  strip  is  made  the  anode  in  an  electric  circuit  and  placed 
in  a  solution  of  di-sodium  phosphate,  it  is  passivified.  It  has  been  shown 
by  Heyn  and  Bauer  that  iron  placed  in  this  solution  will  not  corrode  as 
readily  as  in  solutions  of  commoner  salts,  and  that  a  point  or  "limiting 
concentration "  is  reached  where  all  corrosive  action  ceases.  As  this  phos- 
phate is  used  to  a  certain  extent  as  a  boiler  water  softener,  it  was  decided 
to  study  its  effect  in  solutions  of  sodium  chloride  and  sodium  sulphate  upon 
the  iron  and  steel  used  in  other  experiments.  The  test's  were  conducted  in 
the  same  manner  as  previously  described  and  the  data  obtained  follows: 


COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 
Table  XCI.— Di-sodium  Phosphate. 


Original         Loss  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion 

241 

1/1000 

18.7146 

0.1494 

75 

242 

1/100 

17.1147 

0.0190 

9 

243 

1/10 

18.4924 

0.0005  1 

0 

244 

N 

18.0340 

0.0001  1 

0 

Remarks. 
Badly  corroded. 
Green    and    brown 
No  corrosion. 


rust. 


LOW   CARBON   STEEL.     ROOM   TEMPERATURE. 
Table    XCII.— Di-sodium    Phosphate. 


Original         Loss  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

369 

1/1000 

6.4191 

0.1339 

61 

370 

1/100 

6.9566 

0.0232 

10 

371 

1/10 

7.3431 

0.0004  1 

0 

372 

N 

6.8778 

0.0000 

0 

Remarks. 
'Badly  corroded. 
Greenish  brown  rust. 
No  corrosion. 


COMMERCIALLY  PURE  IRON.     ROOM  TEMPERATURE. 

Table  XCIII.— Sodium  Sulphate  with  N/1000  Di-sodium  Phosphate. 
Original         Loss  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

89 

1/1000 

17.6301 

0.1893 

95 

Badly  corroded. 

90 

1/100 

17.3585 

0.1792 

85 

«             « 

91 

1/10 

18.3143 

0.1850 

93 

"             " 

92 

N 

18.9224 

0.1109 

55 

"             " 

Table  XCIV  —  Sodium  Sulphate  with  N/100  Di-sodium  Phosphate. 

Original  Loss  in  Relative 

Normality.      Weight.  Weight.  Cor'sion. 

1/1000           18.7378  0.0489              24 

1/100           19.5230  0.0505             25 

1/10           19.6386  0.0613              13 


Xo. 
93  . 
94 


X 


0.0861 


33 


Remarks 

\  Covered  with  a  light  brown 
layer     mottled     with 
[      greenish  streaks. 
Badly   corroded. 


1  Gain    in    weight. 


32 


Table  XCV.— Sodium  Sulphate  with  N/10  Di-sodium  Phosphate. 


No. 

Normality. 

Original 
Weight. 

Loss  in 
Weight 

Relative 
.    Cor'sion. 

Remarks. 

97 
98 
99 
100 

1/1000 
1/100 
1/10 

N 

19.2083 
18.5526 
18.9841 
19.6082 

0.0002 
0.0061 
0.0195 
0.0309 

1             0 
3 
10 
15 

No  corrosion. 
Small  lumpy  green  spots. 
Large     "                         " 
Covered  with  brown  rust. 

Table  XCVL—  Sodium 

Sulphate 

with  N/5 

Di-sodium  Phosphate. 

No. 

Normality. 

Original 
Weight. 

Loss  in 
Weight 

Relative 
,    Cor'sion. 

Remarks. 

101 

102 
103 
104 

1/1000 
1/100 
1/10 

N 

20.0196 
19.3779 
19.9065 
18.7244 

0.0004 
0.0000 
0.0032 
0.0266 

1            0 
0 
1 
13 

No   corrosion. 

Small  green  festoons  on  ed 
Greenish-brown    deposits. 

LOW  CARBON  STEEL.     ROOM  TEMPERATURE. 
Table  XC VII.— Sodium  Sulphate  with  N/1000  Di-sodium  Phosphate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

'Weight. 

Weight. 

Cor'sion. 

Remarks. 

209 

1/1000 

7.2392 

0.2221 

Ill 

Badly  corroded. 

210 

1/100 

6.7040 

0.1597 

80 

«             » 

211 

1/10 

7.7197 

0.1862 

93 

«             <« 

212 

N- 

7.2695 

0.1428 

71 

«             « 

Table  XC VIII.— Sodium  Sulphate  with   N/100  Di-sodium   Phosphate. 


Original         Loss  in     Relative 


No. 

Normality. 

'Weight. 

Weight. 

Cor'sion. 

213 

1/1000 

7.0472 

0.0285 

14 

214 

1/100 

7.7363 

0.0304 

15 

215 

1/10 

7.5623 

0.0733 

36 

216 

N 

7.0303 

0.0842 

42 

Remarks. 
Few  small  spots. 
Brown  spots  and  streaks. 
Badly  corroded. 


Table    XCIX.— Sodium   Sulphate    with    N/10   Di-sodium   Phosphate. 


Original         Loss  in     Relative 


No. 

Normality. 

'Weight. 

Weight. 

Cor'sion 

217 

1/1000 

7.7705 

0.0003  1 

0 

218 

1/100 

7.3620 

0.0182 

9 

219 

1/10 

6.6200 

0.0183 

9 

220 

N 

7.7727 

0.0427 

21 

Remarks. 
No   corrosion. 
'Few  minute  green  spots. 

Well    corroded. 


Table  C. — Sodium  Sulphate  with  N/5  Di-sodium  Phosphate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

221 

1/1000 

7.3201 

0.00011 

0 

No  corrosion. 

222 

1/100 

7.6792 

0.0002  ' 

0 

" 

" 

223 

1/10 

7.5185 

0.0093 

5 

Few 

minute    green 

224 

N 

6.9973 

0.0399 

20 

" 

large           " 

spots 


Gain    in    weight. 


COMMERCIALLY   PURE   IRON.   ROOM   TEMPERATURE. 
Table  CL— Sodium  Chloride  with  N/1000  Di-sodium  Phosphate. 


Original 


Loss  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

105 

1/1000 

18.1240 

0.1424 

71 

Badly  corroded 

106 

1/100 

18.9518 

0.1376 

69 

"            " 

107 

1/10 

19.0994 

0.1260 

63 

«            « 

108 

N 

18.0001 

0.1336 

67 

"            " 

Table  CIL— Sodium  Chloride  with  N/100  Di-sodium  Phosphate. 
Original         Loss  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

109 

1/1000 

18.2028 

0.0917 

46 

Badly   corroded 

110 

1/100 

19.1043 

0.0962 

48 

"             " 

111 

1/10 

18.7914 

0.0208 

10 

Green  streaks. 

112 

N 

18.9768 

0.0138 

6 

"     »       " 

Table  CIII—  Sodium  Chloride  with  N/10  Di-sodium  Phosphate. 


Remarks. 
No   corrosion. 
Few  green  spots. 
Large  green  spots. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

113 

1/1000 

18.8776 

0.0003  1 

0 

114 

1/100 

18.9418 

0.0063 

3 

115 

1/10 

17.2943 

0.0350 

17 

116 


X 


19.1335 


0.0243 


12 


Table   CIV. — Sodium   Chloride  with   N/5   Di-sodium   Phosphate. 


No.  Normality. 

117  1/1000 

118  1/100 

119  1/10 

120  N 


Original 


Loss  in      Relative 


Weight. 

Weight. 

Cor'sion. 

Remarks. 

17.3865 

0.0009  ' 

0 

No  corrosion. 

18.1178 

0.0009  1 

0 

"              " 

20.0233 

0.0316 

15 

Green  spots   and 

18.3372 

0.0339 

17 

ii            «        « 

streaks. 


LOW  CARBON   STEEL.     ROOM  TEMPERATURE. 

Table   CV.— Sodium   Chloride   with   N/1000  Di-sodium  Phosphate. 
Original         Loss  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

225 

1/1000 

6.6189 

0.1643 

76 

Badly  corroded 

226 

1/100 

6.6663 

0.1682 

77 

"             " 

227 

1/10 

6.5467 

0.1497 

69 

"             " 

228 

N 

7.4723 

0.1477 

68 

«             n 

Table  C VI.— Sodium  Chloride  with  N/100  Di-sodium -Phosphate. 


Original         Loss  in      Relative 
No.        Normality.      Weight.         Weight.    Cor'sion. 


229  1/1000 

230  -  1/100 

231  1/10 

232  N 


6.7869 
7.6427 
7.0475 
6.8192 


0.0877 
0.0724 
0.0273 
0.0159 


40 
29 
13 

7 


Remarks. 
Badly   corroded. 

Green   streaks   and   spots. 


:  Gain   in   weight. 


34 


Table  CVIL— Sodium  Chloride  with  N/10  Di-sodium  Phosphate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

233 

1/1000 

7.3540 

0.0004 

1             0 

No   corrosion. 

234 

1/100 

6.5625 

0.0048 

2 

Few  minute  green   spots. 

235 

1/10 

7.0781 

0.0344 

15 

Green  streaks   and   spots. 

236 

N 

7.5965 

0.0169 

8 

Table   CVIII.—  Sodium 

Chloride 

with   N/5 

Di-sodium   Phosphate. 

Original 

Gain  in 

(Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks. 

237 

1/1000 

6.3236 

0.0001 

1             0 

No    corrosion. 

238 

1/100 

6.1297 

0.0011 

1             0 

"            " 

239 

1/10 

6.6065 

0.0250 

11 

Green  streaks   and  spots, 

240 

N 

7.5117 

0.0271 

13 

"            "           "         " 

COMMERCIALLY  PURE  IRON.     TEMPERATURE  OF  BOILING  WATER. 


No.  Normality. 

245  1/1000 

246  1/100 

247  1/10 

248  N 


Table  CIX. — Di-sodium  Phosphate. 
Original         Gain  in     Relative 


Weight. 

Weight. 

Cor'sion. 

Remarks. 

17.4359 

0.0143 

269 

Greenish    brown 

streaks. 

17.9364 

0.0102 

194 

"              " 

" 

16.8934 

0.0058 

108 

Green    spots. 

17.0009 

0.0024 

46 

Tarnished. 

LOW  CARBON  STEEL.     TEMPERATURE  OF  BOILING  WATER. 


Table  CX. — Di-sodium  Phosphate. 

Original  Gain  in  Relative 

No.        Normality.     Weight.  Weight.  Cor'sion. 

373  1/1000      6.5418  0.0125     156 

374  1/100      7.0031  0.0110     138 

375  1/10      6.8985  0.0054      68 

376  N      6.5718  0.0019      24 


Remarks. 
Green  and  brown  spots. 


Small  green  spots. 
Well    tarnished. 


COMMERCIALLY  PURE  IRON.     BOILING  TEMPERATURE. 
Table   CXI.— Sodium   Sulphate   with   N/1000   Di-sodium   Phosphate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

333 

1/1000 

19.2281 

0.0170 

321 

334 

1/100 

19.4353 

0.0142 

268 

335 

1/10 

18.1332 

0.0125 

236 

336 

N 

19.3526 

0.0104 

196 

Remarks. 

Spots  over  surface. 
Green  spots. 
Well   tarnished. 


Table    CXIL— Sodium    Sulphate   with    N/100   Di-sodium    Phosphate. 

Original         Gain  in     (Relative 

No.        Normality.      Weight.         Weight.    Cor'sion.  Remarks. 

Green   streaks. 

Green  spots. 

Whole  plate  dull  green. 


337 

i/1000 

19.1982 

0.0156     294 

338 

1/100 

18.3059 

0.0140     264 

339 

1/10 

18.9705 

0.0155     293 

340 

N 

18.7855 

0.0137     268 

JGain  in  weight. 

35 


Table    CXIIL— Sodium    Sulphate    with   N/10   Di-sodium    Phosphate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

341 

1/1000 

19.6320 

0.0146 

275 

342 

1/100 

19.7485 

0.0196 

370 

343 

1/10 

19.5355 

0.0169 

319 

344 


X 


19.2326 


0.0117 


221 


Remarks. 
Well  tarnished. 
Green   spots  and   streaks. 
Badly      tarnished.        Several 
green  spots. 
Green  streaks. 


Table  CXIV.— Sodium  Sulphate  with  N/5  Di-sodium  Phosphate. 


Remarks. 
Tarnished. 
Green  spots. 
Badly  tarnished. 
Green   streaks   and   spots. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

345 

1/1000 

18.4341 

0.0045 

85 

346 

1/100 

19.6283 

0.0143 

270 

347 

1/10 

18.1347 

0.0121 

228 

348 

'   N 

19.0593 

0.0117 

221 

LOW  CARBON  STEEL.     BOILING  TEMPERATURE. 


Table   CXV.— Sodium  Sulphate  with  N/1000  Di-sodium   Phosphate. 


Original         Gain  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

449 

1/1000 

7.3269 

0.0174 

218 

450 

1/100 

7.6484 

0.0202 

252 

451 

1/10 

8.0451 

0.0132 

165 

452 

N 

7.4946 

0.0134 

168 

Remarks 

Green  spots   and  streaks. 
Faint  green  streaks. 
Dull   colour. 
Tarnished. 


TaMe   CXVI. — Sodium   Sulphate  with   N/100   Di-sodium   Phosphate. 


Original         Gain  in      Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

453 

1/1000 

7.7013 

0.0181 

226 

454 

1/100 

7.5766 

0.0200 

250 

455 

1/10 

8.0451 

0.0188 

225 

456 

N 

7.4946 

0.0134 

193 

Remarks. 
Green  spots  and  streaks. 

Green  streaks. 

Many  small  green  spots. 


Table  CXVII.— Sodium  Sulphate  with  N/10  Sodium  Phosphate. 


Original         Gain  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

457 

1/1000 

7.0807 

0.0174 

217 

458 

1/100 

7.4831 

0.0176 

220 

459 

1/10 

7.7700 

0.0191 

239 

460 

N 

7.9405 

0.0142 

178 

Remarks. 
Many  green  spots. 


Table   CXVIII.— Sodium   Sulphate   with   N/5   Di-sodium   Phosphate. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

461 

1/1000 

7.0911 

0.0067 

84 

462 

1/100 

7.6702 

0.0182 

228 

463 

1/10 

7.9916 

0.0136 

170 

464 

N 

7.8441 

0.0122 

153 

Remarks. 
Tarnished.     Small  spots. 

Large       " 
Large   green   spots. 


36 

COMMERCIALLY  PURE  IRON.     TEMPERATURE  OF  BOILING  WATER. 
Table  CXIX.— Sodium  Chloride  with  N/1000  Di-sodium  Phosphate. 


No.        Normality. 

Original 
Weight. 

Gain  in 
Weight. 

Relative 
Cor'sion. 

Remarks. 

349 

1/1000 

19.0371 

0.0136 

257 

Many  green  lumpy   spots. 

350 

1/100 

18.8365 

0.0139 

262 

«          •  1  t          t.             t 

351 

1/10 

16.4222 

0.0098 

185 

Greenish  coating. 

352 

N 

18.5260 

0.0063 

118 

Well   tarnished. 

Table 

CXX.—  Sodium  Chloride  with  N/100 

Di-sodium  Phosphate. 

Original 

Gain  in 

Relative 

No.        Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

353 

1/1000 

18.9083 

0.0096 

181 

Green   streaks  and   spots. 

354 

1/100 

17.0315 

0.0130 

245 

"            "          "          " 

355 

1/10 

18.1345 

0.0100 

190 

Small  green  spots. 

356 

N 

17.5985 

0.0115 

216 

Green  coating. 

Table 

CXXI.—  Sodium 

Chloride  with  N/10 

Di-sodium  Phosphate 

Original 

Gain  in 

Relative 

No.        Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

357 

1/1000 

18.1934 

0.0068 

128 

Few  green  spots  and 

lumps. 

358 

1/100 

17.6379 

0.0110 

207 

Green   spots   and  streaks. 

359 

1/10 

18.3824 

0.0169 

318 

Green    lumps. 

360 

N 

18.2926 

0.0159 

300 

'Green  coating  and  lumps. 

Table 

CXXIL- 

-Sodium 

Chloride 

with  N/5 

Di-sodium  Phosphate 

Original 

Gain  in 

Relative 

No.        Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

361 

1/1000 

18.4672 

0.0020 

38 

Well    tarnished. 

362 

1/100 

18.1511 

0.0044 

83 

Minute    green    spots. 

363 

1/10 

18.1273 

0.0135 

257 

Few  green   lumps. 

364 

N 

18.2734 

0.0151 

288 

Green   lumps. 

LOW  CARBON  STEEL.    TEMPERATURE  OF  BOILING  WATER. 
Table    CXXIII.— Sodium    Chloride    with    N/1000    Di-sodium    Phosphate. 


Original         Gain  in     Relative 


No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

481 

1/1000 

6.7084 

0.0169 

210 

482 

1/100 

6.7072 

0.0153 

191 

483 

1/10 

8.0876 

0.0123 

154 

484 

N 

8.2663 

0.0071 

89 

Remarks. 
Green   coating   with   spots. 

Green  spots  and  streaks. 
Green  coating.    Tarnished. 


Table  CXXIV.— Sodium  Chloride  with  N/100  Di-sodium  Phosphate. 


Remarks. 

Dark   green   coating. 
Green  coating  and  spots. 

Green-brown    coating. 


Original 

Gain  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

529 

1/1000 

6.2168 

0.0091 

114 

530 

1/100 

6.9987 

0.0107 

134 

531 

1/10 

8.1169 

0.0159 

199 

532 

N 

8.2188 

0.0147 

184 

37 


Table    CXXV.— Sodium    Chloride   with    N/10   Di-sodium   Phosphate. 


Original 
No.        Normality.      Weight. 

533  1/1000      7.1474 

534  1/100      6.7447 

535  1/10      6.8138 

536  N      7.4259 


Gain  in  Relative 

Weight.  Cor'sion. 

0.0087  109 

0.0131  164 

0.0149  186 

0.0164  205 


Remarks. 

Tarnished.     Green  colour. 
Spots. 
Green    coating    and    spots. 


Table    CXXVI.— Sodium    Chloride   with    N/5    Di-sodium    Phosphate. 


No.  Normality. 

537  1/1000 

538  1/100 

539  1/10 

540  N 


Original 
Weight. 
7.5677 
6.6022 
7.9037 
7.0790 


Gain  in 
Weight. 
0.0016 
0.0073 
0.0135 
0.0162 


Relative 

Cor'sion. 

20 

91 

169 

203 


Remarks. 
Well  tarnished. 
Pew   green   spots. 
Green   lumpy  spots. 


Room  Temperature. 

Sodium  Sulphate. — 1.  In  all  cases  di-sodium  phosphate  inhibits  corro- 
sion but  not  to  the  extent  manifested  by  potassium  di-chromate. 

2.  With    N/1000    di-sodium   phosphate,    the    rate    of    corrosion    is    only 
slightly  reduced,  but  in  solutions  containing  greater  amounts  of  this   salt, 
the  degree  of  inhibition  is  much  more  marked. 

3.  The   concentration   of  the   sodium   sulphate   remaining   constant,   an 
increase   in   the   amount   of  phosphate   produces   a    decrease   in   the   rate   of 
corrosion.     However,   if  the   sulphate   varies   and   the   concentration   of   the 
phosphate  remains  constant,  an  increase  in  corrosive  action  follows. 

4.  With  solutions  containing  N/100  or  more  of  phosphate,  the  action 
of  the  electrolytes  upon  the  iron  is  shown  by  the  formation  of  dark  green 
or  greenish  brown  spots  and  streaks. 

5.  There  is  a  noticeable  difference  in  the  behavior   of  the  two   types 
of  test-plates. 

6.  When  corrosion  did  not  take  place,  the  test-plates  were  found  to  be 
in  the  active  condition,  as  they  were  readily  attacked  by  1.20  nitric  acid. 

Sodium  Chloride. — The  above  summary  describing  the  action  of  sodium 
sulphate  and  di-sodium  phosphate  also  applies  in  a  general  way  to  conditions 
produced  by  solutions  of  sodium  chloride  and  the  phosphate.  However, 
with  the  normal  solutions  an  increase  of  phosphate  from  N/10  to  N/5  will 
give  a  slight  increase  in  the  rate  of  corrosion.  Further,  if  the  phosphate  is 
kept  constant  and  the  amount  of  sodium  chloride  is  varied  a  decrease  in 
corrosion  sometimes  results,  especially  with  N/100  phosphate. 

* 

Temperature   of  Boiling  Water. 

1.  It  was  found  that  if  di-sodium  phosphate  be  introduced  into  solu- 
tions of  sodium  chloride  or  sodium  sulphate,  an  increase  in  the  rate  of 
corrosion  of  the  test-plates  was  obtained. 


38 

2.  In  N/5  di-sodium  phosphate  there  is  a  general  tendency  for  the  rate 
of  corrosion  to   decrease. 

3.  The  low  carbon   steel  showed  a  higher  rate   of   corrosion  than  did 
the    commercially    pure    iron. 


ACTION   OF   POTASSIUM   BICHROMATE   ON   GALVANIZED   IRON   IN 

THE  PRESENCE   OF   SODIUM  CHLORIDE   AND 

SODIUM  SULPHATE. 

The  use  of  zinc  was  suggested  some  years  ago  as  a  means  for  preventing 
corrosion  in  boilers.  Slabs  of  zinc  were  placed  in  the  boiler  in  contact  with 
the  iron  or  steel,  which  was  preserved  at  the  expense  of  the  zinc.  This 
method  for  preventing  corrosion  was  adopted  on  board  ships  and  made 
particular  use  of  by  tramp  steamers,  the  results  being  highly  satisfactory. 
However,  the  great  objection  to  the  method  is  the  rapid  manner  in  which 
the  zinc  will  go  into  solution  under  boiler  conditions.  As  Dunstan  and 
Hill l  have  shown  that  zinc  can  be  passivified  by  means  of  potassium 
dichromate,  and  in  view  of  the  fact  that  this  salt  will  greatly  reduce  the 
rate  of  corrosion  of  iron  and  steel  in  the  presence  of  large  amounts  of 
common  boiler  salts  at  room  temperature,  as  shown  in  previous  experiments, 
it  was  thought  that  possibly  the  rate  of  solution  of  the  zinc  would  be  like- 
wise reduced  in  the  presence  of  potassium  dichromate  without  hindering 
it's  action  toward  the  iron.  Accordingly  solutions  of  varying  concentrations 
of  sodium  chloride  and  sodium  sulphate  containing  potassium  dichromate 
in  different  amounts  were  made  up,  and  test-plates  of  galvanized  iron, 
similar  in  size  to  those  previously  used,  were  introduced  into  the  solutions. 
Tests  were  run  both  at  room  temperature  and  at  the  temperature  of  boiling 
water  for  two  weeks.  The  conditions  under  which  the  tests  were  performed 
were  the  same  as  given  on  p.  10. 

In  cleaning  the  plates  after  they  had  stood  in  the  solutions  great  diffi- 
culty was  experienced.  After  trying  several  means  for  cleaning  them,  it 
was  decided  to  simply  wash  them  thoroughly  with  water  and  then  with 
alcohol  and  dry.  It  was  found  to  be  almost  impossible  to  secure  very  good 
checks  on  the  tests.  This  is  attributed  to  improper  means  for  cleaning, 
formation  of  zinc  chromate,  and  to  the  great  variation  in  the  size  of  the 
crystals  of  zinc  on  the  galvanized  iron.  The  rate  of  solution  of  the  plates 
in  water  was  taken  as  a  standard. 

Tests  were  run  with  solutions  containing  varying  amounts  of  potassium 
dichromate.  The  plates,  after  standing  for  a  brief  period,  especially  in  the 
stronger  solutions,  became  very  bright;  but  at  the  end  of  the  two  weeks 
it  was  observed  that  much  more  zinc  had  gone  into  solution  than  when  the 
plates  were  immersed  only  in  water.  This  is  easily  explained  by  the  fact 
that  the  addition  of  the  potassium  dichromate  would  increase  the  con- 
ductivity of  the  solutions  and  thus  cause  an  increase  in  galvanic  action. 

A  glance  at  the  following  results  will  show  that  the  presence  of  potas- 
sium dichromate  in  either  solutions  of  sodium  chloride  or  sodium  sulphate 

1  Transactions  of  the  Chemical  Society,  vol.   99,  p.  1861. 


39 

will  stimulate  the  solution  of  the  zinc  rather  than  inhibit  it.  If  the  amount 
of  potassium  dichromate  is  kept  constant  and  the  concentration  of  the 
sodium  chloride  or  sodium  sulphate  is  increased,  the  rate  of  the  destruction 
of  the  zinc  is  increased.  Further,  if  the  concentration  of  the  potassium 
dichromate  is  varied  and  that  of  the  sodium  chloride  or  sodium  sulphate 
kept  constant,  the  rate  at  which  the  zinc  is  attacked  is  far  more  vigorous. 

The  plates  immersed  in  the  more  concentrated  solutions  of  potassium 
dichromate  and  sodium  sulphate  or  sodium  chloride  were  all  of  a  yellow 
colour,  the  intensity  of  which  depended  upon  the  strength  of  the  solutions. 
After  these  plates  had  been  thoroughly  washed  with  water,  they  were 
treated  with  hydrochloric  acid  to  dissolve  the  zinc  together  with  the  yellow 
coating.  The  resulting  solutions  were  tested  for  chromium.  In  every  case 
this  element  was  identified,  much  more  chromium  being  found  in  the  solu- 
tions obtained  from  the  plates  having  the  deep  yellow  color  than  those 
possessing  a  lighter  color.  Thus  the  yellow  deposit  on  the  galvanized  iron 
was  due  to  the  formation  of  zinc  chromate. 

With  the  tests  run  at  the  temperature  of  boiling  water  no  quantitative 
results  were  obtained.  In  every  case  the  plates  were  badly  attacked,  and 
in  some  instances  flakes  of  metallic  zinc  had  fallen  from  the  plates.  In 
many  others  all  the  zinc  had  dissolved  and  the  solutions  had  attacked  the 
iron.  This  was  especially  true  of  the  sodium  chloride  solutions. 

GALVANIZED  IRON.     ROOM  TEMPERATURE. 

Table  CXXVII.— Action  of  Water. 

Original  Loss  in 

No.  Weight.  Weight.                                  Remarks. 

A  5.9566  0.0023                             No  visible  action. 

B  6.1762  0.0029 

C  6.2771  0.0038 

D  5.9928  0.0032 

E  «.0821  0.0026 

Table    CXXVIII. — Potassium   Dichromate. 

Original         Loss  in      Relative 
No.        Normality.      Weight.         Weight.     Cor'sion.  Remarks. 

525  1/1000  5.8927  0.0039  130          No    visible    action. 

526  1/100  6.1605  0.0021  70  Metal    brighter. 

527  1/10  6.3310  0.0064  213          Metal  bright. 

528  1/5  6.4807  0.0065  216 

GALVANIZED  IRON.     ROOM  TEMPERATURE, 

Table   CXXIX.— Sodium   Sulphate   with   N/1000  Potassium   Dichromate. 

*  Original         Loss  in      Relative 

No.        Normality.      Weight.         Weight.    Cor'sion.  Remarks. 

485  '    1/1000  5.7442  0.0059  197          No  visible  change. 

486  1/100  5.4649  0.0064  213 

487  1/10  5.7579  0.0088  293 

488  N  6.1893  0.0114  380 


40 
Table   CXXX. — Sodium  Sulphate  with  N/100  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks. 

489 

1/1000 

5.5231 

0.0159 

530 

No  visible  change 

490 

1/100 

5.8883 

0.0320 

1063 

"          "            " 

491 

1/10 

5.5643 

0.0383 

1277 

Light  yellow  in  color. 

492 

N 

5.7842 

0.0775 

2583 

Table 

CXXXL—  Sodium 

Sulphate 

with    N/10 

Potassium   Bichromate, 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks. 

493 

1/1000 

5.7247 

0.0114 

380 

No  visible  change 

494 

1/100 

5.5725 

0.0345 

1150 

Light  yellow. 

495 

1/10 

5.7728 

0.0528 

1760 

Deep    yellow. 

496 

N 

5.4051 

0.0649 

2163 

Table 

CXXX1L—  Sodium  Sulphate 

with  N/5 

Potassium  Bichromate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.     Cor'sion. 

Remarks. 

497 

1/1000 

6.0362 

0.0171 

570 

No  visible  change 

498 

1/100 

5.2548 

0.0389 

1297 

Deep   yellow. 

499 

1/10 

6.0078 

0.0950 

3167 

"            " 

500 

N 

5.7815 

0.0986 

3287 

"            " 

GALVAXIZEB  IRON.     ROOM  TEMPERATURE. 


Table  CXXXIIL— Sodium  Chloride  with  N/1000  Potassium  Bichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.    Cor'sion. 

Remarks 

501 

1/1000 

5.8586 

0.0052 

173 

No  visible  change. 

502 

1/100 

5.8087 

0.0097 

323 

"          "           ' 

503 

1/10 

5.3215 

0.0061 

203 

"          "           ' 

504 

N 

5.1719 

0.0097 

323 

"          "           " 

505 

3  N 

5.5820 

0.0145 

483 

"          "           " 

506 

5  N 

6.1767 

0.0210 

700 

Table 

CXXX  IV.- 

-Sodium 

Chloride 

with    X/100 

Potassium 

Bichromate. 

Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight 

.     Cor'sion. 

Remarks 

507 

1/1000 

5.9378 

0.0062 

207 

No  visible  change. 

508 

1/100 

6.0623 

0.0248 

827 

a          «           a 

; 

509 

1/10 

6.1338 

0.0398 

1327 

"          "           '' 

I 

510 

N 

6.3237 

0.0568 

1893 

"          "           " 

511 

3  N 

6.0456 

0.0675 

2250          Light  yellow  in   color. 

512 

5  N 

6.0240 

0.0691 

2333 

"            "        ' 

(               " 

41 
Table    CXXXV.— Sodium    Chloride    with    N/10    Potassium    Dichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

513 

1/1000 

6.3159 

0.0055 

183 

514 

1/100 

5.8117 

0.0270 

900 

515 

1/10 

5.8750 

0.0694 

2313 

516 

N 

6.1337 

0.0987 

3290 

517 

3  N 

6.0204 

0.0981 

3270 

518 

5  N 

H.9321 

0.113a 

3767 

Remarks. 
No  visible  change. 

Light  yellow  in  color. 
Deep  yellow. 


Table    CXXXVI. — Sodium    Chloride    with    N/5    Potassium    Dichromate. 


Original 

Loss  in 

Relative 

No. 

Normality. 

Weight. 

Weight. 

Cor'sion. 

Remarks. 

519 

1/1000 

5.9914 

0.0018 

60 

No  visible  change. 

520 

1/100 

5.9276 

0.0282 

940 

"          "           " 

521 

1/10 

6.0575 

0.0713 

2377 

Light  yellow. 

522 

N 

6.1311 

0.0909 

3030 

Deep  yellow. 

523 

3  N 

5.9955 

0.0987 

3290 

"           " 

524 

5  N 

6.2547 

0.1006 

3353 

"           " 

THE     EFFECT     OF     THE     ELECTRIC     CURRENT     AND     POTASSIUM 
DICHROMATE  IN  VARIOUS  SOLUTIONS  UPON  AN  IRON  ANODE. 

A  study  of  the  behavior  of  an  iron  anode  in  various  solutions  containing 
potassium  dichromate  and  heated  to  high  temperatures  was  undertaken. 
A  small  boiler  containing  a  pressure  gauge,  a  safety  valve  and  a  common 
spark  plug,  which  was  screwed  into  the  top  of  the  boiler,  was  constructed. 
The  entire  boiler  was  made  the  cathode  in  an  electric  circuit  and  a  small 
strip  of  iron  suspended  from  the  spark  plug  was  used  as  the  anode. 

The  iron  strips  which  were  used  as  anodes  were  made  from  commer- 
cially pure  iron  and  had  the  following  dimensions :  10  cm.  X  0.50  cm.  X  0.10 
cm.  The  total  area  was  12.10  square  centimetres.  A  small  hole  was  drilled 
into  the  top  of  each  strip  so  that  it  could  be  hooked  on  to  A.  When  the 
plug  was  screwed  into  the  top  of  the  boiler,  the  iron  strip  would  be  com- 
pletely covered  by  the  solution.  The  hole  in  the  strips  decreased  the  area 
exposed  to  11.97  square  centimetres. 

The  boiler  was  heated  by  placing  in  a  large  paraffin  bath. 

N/10  solutions  of  sodium  sulphate,  sodium  chloride,  magnesium  sulphate, 
and  magnesium  chloride  were  used.  To  these  solutions  potassium  dichro- 
mate was  added  until  they  were  also  equivalent  to  N/10  and  N/5  solutions 
of  this  substance. 

In  running  the  experiments  the  solutions,  which  would  be  at  room  tem- 
perature, were  introduced  into  the  cool  boiler.  The  iron  strip  was  then 
introduced  into  the  solution,  and  the  plug  from  which  it  was  suspended 
screwed  securely  into  the  top  of  the  boiler.  The  proper  electrical  connec- 
tions were  made,  so  that  a  current  of  two  and  a  half  amperes  flowed  through 


42 

the  system.  The  boiler  was  then  immediately  placed  in  the  paraffin  bath 
and  heated  rapidly  until  a  pressure  of  120  Ibs.  was  recorded  upon  the  gauge. 
At  the  end  of  half  an  hour  the  boiler  was  removed  from  the  bath,  and  when 
cool  enough  the  current  was  stopped  and  the  iron  strip  removed.  In  every 
case  it  was  found  that  the  iron  would  be  in  the  active  condition,  as  a  large 
part  of  it  had  gone  in  solution  during  the  half  hour  treatment. 

Tests  were  then  run  starting  with  warm  solutions  containing  normal 
(147  grammes  per  litre)  potassium  dichromate  in  N/10  solutions  of  the  four 
salts  previously  used.  Upon  repeating  the  experiments  as  described  above, 
the  same  results  were  obtained,  the  increase  in  the  amount  of  potassium 
dichromate  producing  no  effect.  A  warm  solution  was  used  at  the  start  to 
dissolve  all  the  potassium  dichromate. 

Thus  it  may  be  concluded  that  the  possibility  of  keeping  iron  passive 
under  boiler  conditions  with  the  aid  of  an  electric  current  and  potassium- 
dichromate  is  practically  impossible. 

GENERAL  CONCLUSIONS. 

1.  At  atmospheric   conditions  the  introduction   of  varying  amounts  of 
potassium   dichromate   into   solutions   of  different   concentrations   of  sodium 
sulphate,  sodium  chloride,  magnesium  sulphate  and  magnesium  chloride,  and 
saturated  calcium  sulphate,  inhibit  corrosion  t'o  a  remarkable  extent. 

2.  The  differences  in  the  chemical  composition  and  physical  properties 
of  the  iron  and  steel  employed  appeared  to  have  practically  no  effect  when 
placed  in  solutions  of  chlorides  and  sulphates  containing  potassium  dichro- 
mate   at    room    temperature.      Differences    in    behavior    were    noted    at    the 
temperature   of  boiling  water. 

3.  At   atmospheric   conditions   a   few  of  the   test-plates  were  rendered 
passive  by  the  dichromate  contained  in  certain  of  the  more  dilute  solutions. 

4.  The  rate  of  corrosion  was  reduced  in  some  cases  upon  the  addition 
of  dichromate  to  the  dilute  solutions  at  the  temperature  of  boiling  water. 

5.  In   N/10   and  normal   solutions   of  the   chlorides   and   sulphates  the 
addition  of  dichromate  to  the  hot  solutions  was  decidedly  injurious  to  the 
iron  and  steel. 

6.  The     commercial    application    of    potassium    dichromate    to    boiler 
waters  is  not'  practicable  because  of  cost  and  uncertainty  of  results. 

7.  Di-sodium   phosphate   limits  the  rate   of   corrosion   of  the   iron   and 
steel    at    room    temperatures    when    added    to    various    solutions    of    sodium 
sulphate  and  sodium  chloride. 

8.  Di-sodium  phosphate  does  not  produce  the  passive  state  when  iron 
or  steel  is  immersed  in  its  solutions. 

9.  Slight  differences  in   the   action   of  the  iron  and  steel  in  solutions 
containing  di-sodium  phosphate  were  noted. 


43    . 

10.  Iron  and  steel  in  solutions  of  sodium  sulphate  and  sodium  chloride 
containing   di-sodium   phosphate  and  heated  to   the  temperature   of  boiling 
water,  are  more  readily  acted  upon  than  if  the  phosphate  were  not  present. 
Even  small  amounts  of  this  salt  increase  the  rate  of  corrosion. 

11.  The  rate  of  solution  of  zinc  occurring  on  galvanized  iron  is  increased 
by  the   addition   of  potassium   dichromate  to   solutions   of   sodium   sulphate 
and  sodium  chloride. 

12.  Iron   cannot  be  rendered  passive  under  boiler  conditions  in  N/10 
solutions   of   chlorides   and   sulphates   when   varying   amounts   of   potassium 
dichromate  are  added  and  the  iron  made  the  anode  in  an  electric  circuit. 

The  author  of  this  paper  is  indebted  to  the  Iron  and  Steel  Institute  of 
Great  Britain  for  financial  assistance  given  through  the  Carnqgie  Scholarship 
Fund. 


44 


VITA. 

The  author  of  this  paper  was  born  in  Rose  Bank,  Staten  Island,  N.  Y. 
He  received  his  early  education  in  the  grammar  schools  of  Brooklyn,  N.  Y., 
and  graduated  from  the  Commercial  High  School  of  that  city  in  1906. 
Immediately  after  graduation  he  accepted  a  position  in  the  chemical  labora- 
tories of  the  American  Brass  Co.  of  Torrington,  Conn.,  and  was  employed 
there  until  September.  1911.  He  then  entered  Clark  College,  Worcester, 
Mass.,  and  received  the  degree  of  Bachelor  of  Arts  from  that  institution 
in  1914.  While  a  student  at  Clark  some  time  was  spent  in  the  chemical 
laboratories  of  the  American  Steel  and  Wire  Co.  as  assistant  chemist.  In 
the  fall  of  1914  he  entered  the  University  of  Washington  as  teaching  fellow 
in  chemistry.  The  degree  of  Master  of  Science  was  granted  in  the  summer 
of  1915.  During  this  year  papers  on  the  "Total  Amino  Nitrogen  in  the 
Seedlings  of  the  Alaska  Pea"  and  the  "Tannin  Content  of  Pacific  Coast 
Conifers",  the  latter  with  Dr.  H.  K.  Benson,  were  published.  In  the  same 
year  a  Carnegie  Research  Scholarship  was  received  from  the  Iron  and  Steel 
Institute  of  Great  Britain.  The  years  1916  and  part  of  1917  were  spent  in 
graduate  work  at  the  University  of  Washington.  In  June  of  the  latter 
year,  the  examinations  for  First  Lieutenant  in  the  Ordnance  Department 
were  passed  but  no  call  into  active  service  was  received  until  December. 
Being  among  the  first  drafted  in  July  of  that  year,  he  served  a  month  at 
Camp  Lewis  as  a  private  and  two  months  with  the  Gas  Defense  Service, 
working  in  the  laboratories  of  the  National  Carbon  Company,  of  Cleve- 
land, Ohio.  As  First  Lieutenant  he  worked  in  the  Geophysical  Lab- 
oratory of  Washington,  D.  C.,  the  laboratories  of  Ohio  State  University, 
Johns  Hopkins  University,  and  of  Edgewood  Arsenal.  All  of  the  work 
performed  in  these  laboratories  dealt  with  the  chemistry  of  war  gases.  In 
July,  1918,  he  was  transferred  to  the  Chemical  Warfare  Service  with  the 
rank  of  captain. 


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